composting head sailboat

Poop in a Bucket – Thoughts on our Composting Head

“Oh no, it’s poop again!”

While we probably have received the most inquiries about where our mast is , questions about our composting toilet are definitely number two. Hehe.

Replacing our traditional marine flush toilet and holding tank with a composting toilet was the first big boat project we did after purchasing our Tartan 37 . We have been living with our composting toilet for a while now and have gotten a feel for pooping in a bucket so to speak, and would like to share with those who are curious about making the switch.

As with most decisions, we approached this one fairly methodically, however in full disclosure, there was one pretty major factor that influenced our decision:

We already owned the composting toilet.

We actually purchased the composting toilet (before buying our Tartan 37) to put into another boat we had under contract, because that boat had no toilet whatsoever, and the composting toilet was going to be the easiest/quickest to install. When that boat purchase fell apart we were left without a boat — but we had a brand new composting toilet!

Back to our decision making process…

One thing we loved about our Tartan was that she smelled amazingly good. No diesel odor, no mold or mildew, and the distinct odor of human waste — inescapable on many boats — was nonexistent. Much of this was due to the previous owners never using her as a full-time liveaboard. She was kept at a dock, sailed mostly on weekends and the occasional multi-week summer trip — all in FRESH WATER. To top it all off, she was well-loved by her previous owners, who kept her in immaculate condition.

And we were about to change all of that completely . We planned to liveaboard, and saltwater was in our future.

During our shake down sail across lake Michigan , our plan was to figure out what worked and what didn’t. We wanted to figure out what we absolutely needed to change right away, and would go on the back burner for the future. Besides having a wonderful time Cruising Lake Michigan , we came back with a punch list of changes we wanted to make before traveling full-time.

At the top of that list was replacing our marine head and holding tank.

Why We Replaced our Marine Head with a Composting Toilet

We quickly realized that the only reason the head didn’t smell was because it wasn’t really being used. Once we started using it, that changed quickly. And the smell permeated everything. Even when you weren’t physically using the toilet at that very moment, the smell was there. It was disheartening.

During one rough passage, we went down below to see water backing up into the bathroom sink and the toilet bowl. My first thought was that water was coming up the thru-hull and filling them both up, since we were beating into some heavy winds and heeling over pretty good. I quickly remembered that we had a Y-valve under the sink that allowed fresh water to be pumped into the toilet from the sink, or raw water from the thru-hull; I figured it had been left in the wrong position allowing water from the lake to enter the boat through the sink and siphon down into the toilet. So I closed it, and went back up on deck.

Still being rather new to the boat, I thought I had solved the problem. Ten minutes later I went below to check up on the situation…

AND IT WAS SO MUCH WORSE.

Now there was much more water in the toilet bowl and the sink than before and it was brownish in color and it was spilling out into the head pan with each wave we crashed into! All the reading I had done about disasters at sea and how to survive them did not prepare me for this one…this was a different kind of disaster I hadn’t imagined.

As many of you know, the joke was on us — our joker valve was bad — but it was exactly at that moment we knew we never wanted to deal with that situation again. We pulled out the holding tank as soon as we got back to the dock.

Composting Toilets vs. Marine Head & Holding Tank

There are a number of benefits to replacing our marine head with a composting toilet, in addition to simply avoiding sewer water splashing about the boat:

We can go longer between ‘removing’ our waste. We used to have a 12-gallon holding tank in the v-berth. This is pathetically small. The two of us together generate just over 1 gallon of liquid per day, then adding solids and the water required to flush, means we could go maybe 5 days between pump-outs — if we were lucky!?! We can go a good week and a half before needing to empty the composter — and this is using the smaller 3-gallon C-Head which we had to go with because of the smaller size of our bathroom/head.
We reduced weight onboard. 12 gallons of liquid/solids is heavy! We didn’t like having all that weight at the pointy end of our boat.
We opened up more storage space for other things. We gained a bunch of storage room under the v-berth, and completely opened up the previously unusable hanging closet aft of that once we removed all the massive hoses and plumbing that ran through it connecting the head to the holding tank.
The smell literally disappeared. The only smells we have now are when we open the lid to the toilet, and to be honest it’s mostly the liquids that smell. (And a spritz of vinegar into the bowl helps with this.) The solids portion of the toilet is quite tolerable.
We get to choose when to deal with emptying the waste. We don’t have to be back at a dock every few days to get a pump-out.
We save money not paying for pump-outs.
We save the precious fresh water that was once used to flush.
We closed off an unnecessary thru-hull.
There are almost no moving parts, almost nothing that could break, and next to NO maintenance — just cleaning.
If anything does break, every single component can be easily sourced and fabricated anywhere in the world. It’s literally a bucket with some PVC pipe inside.
There is really only one negative. It shows itself a few different ways, and can be a big turn off for some: You will be physically more intimate with your solid waste. With a traditional marine head, you don’t really have to deal with it until something breaks, but then you’re really up close and personal with it. You can pump a lever to flush it out of sight and into the holding tank. You then pay someone to pump it out of your boat and haul it away for you. Essentially once you’ve done your business you may never need to see it again. Unless of course, UNTIL SOMETHING BREAKS. And it will, at the worst time, in the worst place, and it won’t be pretty. With the composter, you’ll be dealing with it yourself on regular basis, but with much less drama. After you do your business you’ll need to cover it with a composting medium, then once the container is full you’ll empty it yourself. It doesn’t get flushed away, you won’t be paying someone to remove it. But — and it’s a huge BUT — doing so makes all the difference. Solid waste in the composter is so much more tolerable than the soupy sludge found in clogged marine toilets and holding tanks. So if you can get over the initial ick factor, it’s so totally worth it.

Thoughts on the C-Head

There are a number composting toilet options available: Nature’s Head , Airhead , and C-Head , to name a few.

They are all fundamentally the same device, and function in a very similar way: they each separate solids from liquids, churn up the solids to keep them covered and empty when needed.

Each may perform these tasks in a slightly different manner, but choosing between the available options is likely to be based more on size and price than any available specific features.

We went with the C-Head and are quite happy with our decision. Besides being the smallest option (which was necessary to get it to fit next to the contour of the hull in our head) it was also the cheapest which was a nice bonus. And to top it all off, it was built by a sailor specifically for sailors. This becomes obvious in a few key areas we’ll point out below. The Nature’s Head seems to be marketed more towards off-grid living as a replacement for a normal household toilet, and the Airhead seems a little more RV-oriented.

The C-Head is dead simple, and aside from the faux teak which blends in nicely with the rest of our interior, the remaining parts and pieces could be sourced anywhere in the world, if there was ever a repair needed. The agitator is made out of common PVC pipe, the liquids container is a milk jug that can be replaced with any other milk jug at any time. And the solids container is literally a 3- or 5-gallon bucket. Minimalism and simplicity are awesome.

The other major advantage of the C-Head for us was the simplicity of cleaning and emptying. Remember this is the one big negative for composting heads — you have to deal with your waste yourself — so seeing as it’s just a 5-gallon bucket, it is incredibly easy to dispose of the waste, whether it’s over the side while offshore, or into a garbage bag when appropriate, hosing it down and bleaching it if need-be or dragging it through the saltwater, all makes quick work of the job when you want to get it cleaned up.

Would we make the same decisions again if in a similar situation? Yes, absolutely. We’re very happy with the composting toilet, and happy with our choice of a C-Head.

If we could design our perfect waste-disposal system, in our perfect boat?

It would be this: A composting toilet for in-shore business in one hull, and a traditional marine head (no holding tank) for going straight into sea while offshore in the other hull. Yup you read that right — two hulls. We can dream. 😉

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18 comments.

Good post, Thanks

Thanks Kirk for the post. I’m getting ready (ugh) to change out my smelly old hoses in my boat. If that doesn’t do the trick the C-head will be my number 1 & 2 option….

This stinks, total shit show, UnCAN-ey, my (head) is spinning, 😂 I’m think I’m puny.

Those are some $h*tty jokes.

Our head and tank haven’t caused any drama for us, so a C-head has been a low priority. That said, we’d love to do for out Tartan what you’ve done, and maybe dedicate the space recovered to a water maker of some sort, using the thru-hull for water intake.

Sounds like a great idea! We used the extra space where the holding tank was for spares. If we decided to get a watermaker we agreed we’d pull the port water tank and put it there. Which would still give pretty easy access to that through-hull, but would also open up a bunch of extra can-food and tool storage.

Great interesting Post, All the best guys xx

I am also considering a liveaboard in the next year or two, and I ‘think” I am sold on the Tartan 37 too. It seems to have good sailing traits, and quite seaworthy, as well as a great vessel that keeps much of it’s value if taken cared for and modernized when needed! It’s seems big enough for two, although I plan on being solo. What about being solo? Could you imagine swinging that? MY dream, is to navigate the Caribbean first, but toward Aruba, then maybe thru the Panama Canal to Costa Rica? THis is a good enough vessel for this? I think YES! I like the idea of the composting toilet. THanks so much for sharing your experiences!! Nick

Sounds like an awesome plan. With the right upgrades, any boat can be set up for solo-sailing, just depends on how many electronic gadgets you want to rely on. That said I think the T37 would be easily single handed. The only area that’d be tough for us to solo is anchoring, but that was a conscious choice to go with an electric windlass. Swap out our manual for an electric and you’d be set. Our main halyard runs to the cockpit, the jib sheets are in reach while at the wheel, the mainsheet is on the coachhouse but it’s easily run back to the helm while under sail, or with the autopilot, it takes just a moment to make an adjustment. The boat’s not so big that you can’t push it around by hand in most wind conditions while at the dock, and it is sized perfectly for two, one would be fabulous!

Hey, Kirk – Thanks for the breakdown on the composting toilet. A few questions come to mind: What is the composting medium that you’re using? Will you be able to find it outside the U.S.? When you’re at a dock, where do you empty the liquid waste container (overboard?)? Lastly, (probably a novice question) Does the sink go to another holding tank?

We started using aspen shavings, and have purchased coconut coir to try that out when the aspen shavings run out. We have enough for a number of months right now. I’m sure we’ll be able to find something no matter where we go. When we’re at the dock we rarely use the head, and prefer to use the shore facilities. The sink drains directly into the water, no holding tank. We know a number of cruisers, who even with a holding tank, prefer to deposit liquids into a separate container, and then actually dump that through their sinks or overboard.

We had a C Head in our last boat and were very pleased with it. So much so that we now have a Nature’s Head on our current boat. We experimented with media as well and have ended up using the coconut coir. If you are not actively cruising and the head will be left for periods of time, we found that it is a good idea to pre-bake the coir in an oven prior to stocking it on the boat. That will kill off any insect eggs that may be hiding in the coir. Twice prior to starting this practice we returned to a boat full of small friends that we had to clean up, so I researched it a bit and discovered the baking trick. Even so, we have found that the coir is our go to media now and will remain so, for what it’s worth. Good luck out there.

Good tip! Thank you for sharing. We just ran out of aspen shavings and are trying the coir now. So far the coir does a better job of pest control, but we actually miss the smell of the aspen shavings it was like walking into a high-end closet, or a crisp mountain forest. The coconut coir doesn’t necessarily smell bad, but is definitely more “earthy”.

Hey guys, fellow T37 owner. Yesterday I ended up with a v-berth full of blackwater. It’s time to make the leap to a C-Head. Which model did you guys use?I think that the Wedgeback looks like what would work the best. Also, did you buy the kit that seals it all up when you shower, as to avoid getting liquid in the dry compartment?

Hi Jason, that sounds familiar! We did not get the shower kit, we don’t actually use the head for showering. It looks like he’s changed the models he’s offering a bit, but ours does have an angled back like the ‘Wedgeback’. That fit the space just perfectly. Good luck!

Your boat probably was not equipped with any valve allowing you to dump your waste overboard as it was a freshwater boat. I removed my head and replaced it with an electric macerator toilet and installed all new plumbing and holding tank. I use RV toilet solution and I have zero smell. The sink drain and toilet intake were connected to the same thru hull and this resulted in water getting into the toilet bowl when you drained the bathroom sink as it couldn’t drain fast enough before it backed into the head.

I ended up adding a valve between the intake and thru hull and it fixed up the back up problem. You just need to remember to open the valve up before you flush and close it when you are done and my bowl stays dry and smell free.

I considered composting but I do not live on my boat so it’s used sporadically and not as my daily toilet.

Having an electric toilet is a big plus when you have kids. They simply push a button to flush and they don’t need to do the manual pump stuff.

Thanks for all you share about your projects and adventures! We bought a T37 (hull 248) a few months ago and have decided to install a CHead. Do you happen. To have the dimensions of the board and bracing you used to build out the platform for yours? I’m not sure we can orient ours straight like you have and still close our door, my OCD really wishes we could have it straight though!

Hi Jen, We don’t. I’ll take some measurements next time we’re at the boat. But two important points. We have the angled base version of the c head, allowing us to push it back as far as possible, and it only clears the door by about a quarter inch. 🙂

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Composting Head Disposal Options

W e wouldn’t describe ourselves as huge fans of composting/desiccation heads (see “ Dissecting the Desiccating Head ,” PS July 2021). We’re not encouraging people to rip out what they have or even to go that way with replacements; a properly installed and maintained holding tank system works very well and fits the needs of most sailors. We see composting/desiccating heads as a solution when pump out facilities are sparse or non-existent as in some lakes and rivers, to save weight and space in small boats, for day sailing when head use is minimal, and for severe winter situations when freezing becomes a problem.

Some people are offended by the very idea of composting heads, or can’t see themselves using such a system. As a result, any disposal option for composted waste offends them. Taste, however, does not determine the “rightness” of either system, and neither is perfect. What matters is that each disposal method is carried out safely without an undue risk to the user or the communities impacted.

The waste from composting toilets in continuous use is not true compost. It is partially digested, desiccated solid waste. This designation is the source of some of most objections to common disposal methods, which is to throw the desiccated waste into the nearest dumpster. In the minds of many, solid waste belongs only at a solid waste treatment facility. But we’ve long accepted some forms of waste disposal that don’t meet this standard. Dumpsters legally accept diapers, bathroom waste, household infectious waste and household sharps (needles), as well as dog and cat waste. There is no expectation or requirement to restrict dumpster waste to stuff you can safely swim in.

It is worth noting that waste removed at a pump-out station also comes with some health risks. Sewers legally accept human infectious waste and even hazardous waste within certain industrial permits, a nasty mix that sewer and treatment plant workers are in contact with every day. Workers who pump out portable toilets deal with this through a combination of personal protection equipment, hand washing, and vaccines.

When you pump out your holding tank into a municipal systems, that’s not the end of it. When it rains, municipal systems overflow into local waters, and even separate sewer lift stations can overflow due to mechanical and power problems. The difference between your composting head and municipal systems is that everything related to municipal sewage is defined and regulated. Since the rules for disposing composted waste are still nebulous, it is up to us, the community of users, to develop safe and responsible best practices for composting toilets.

ISOLATED PROBLEMS

After interviewing fellow cruisers and researching the topic, we found remarkably few reports of controversy over disposal of composted waste. We also were unable to find many rules that had been introduced to help manage any conflicts linked to disposal of composted waste. Here are examples of the isolated problems we found.

ANNAPOLIS HARBOR

Located in our local cruising area, we’ve spoken with the harbor master on several occasions. The root of the problem is a few individuals who dump their waste in the typical coffee cup waste bins located alongside the park benches at the dinghy dock, instead of walking their waste a mere 50 yards to the city dock dumpster serving the municipal marina. The cans fill up, overflow, and townspeople, not unreasonably, complain. The result is a city requirement that all visiting boats use the pump-out service at least once every two weeks, or they will be asked to leave.

CANYONLANDS

Desert campers placed too many WAG bags in small bins at Canyonlands National Park, which ruptured when the trash compactor squeezed them. This really should not have been a surprise, because just weeks earlier the Park Service issued a new mandate requiring all campers to carry out their waste. I’m sure the cans at the trail head seemed to be the logical receptacle, placed there for that reason. The Park Service immediately labeled the cans “No WAG Bags” instead of recognizing they triggered the problem. Note that WAG bags contain liquid waste as well as solids, use less absorbent, and are sealed immediately after each use, which prevents the natural desiccating process. The waste in a wag-bag is very different from composting/desiccating toilet waste.

CANAL AND RIVER TRUST, UK

The canal system is home to many liveaboards, the pump out system (Elsan) is relatively expensive ($20-$30 per use versus $5-$10 in the US), and is not always convenient to boats that don’t move constantly. Combine that with small waste bins, the contents of which are manually sorted for recycling (no separate recycling containers), and it has become a practical problem. The Canal Trust, a non-profit which manages the canal and trail system issued a position statement March 2021 requesting that solid waste not go in their bins and that boats convert to holding tank systems. Diapers are still permitted.

BEST MANAGEMENT PRACTICES

By adhering to best management practices for composting heads we can prevent this sort of blowback. Based on our research, the following is what we’d consider safe, reasonable practices.

Proper head operation is vital not only to eliminate odor and maintain user satisfaction, but also to ensure that waste products are stable and non-objectionable. Urine must be separated from the solids through careful use of the separating seat. Mixing urine with solids increases odors and results in a sloppy product.

An anti-odor treatment, such as vinegar, citric acid, or Nilodor will keep the urine inoffensive when disposed in a rest room (see “ Additives Fight Urine Odor ,” and “ Wood Ash Absorbs Odor Best ,” PS July 2021). Sufficient effective absorbent and adequate ventilation results in a desiccated product with minimal odor and reduced spill potential. Do not wait until the head is overfull, since a little extra absorbent should be added prior to disposal. Adjust these recommendations to suit your specific equipment and situation.

Responsible management and discreet disposal are the goal.

Urine Container. Disposal in a public restroom is the preferred option; treated urine is nearly odor free. Disposal in the woods, well away from the water, is acceptable in remote areas.

Solids. Adding our solid waste to a composting system is the best option for solids when practical. I’ve done this with land-based systems, but not on the boat. Because our test boat is primarily day sailed, the head is used only a few times each year. If I cruised locally and lived near the boat, we would add our boat waste to our compost pile. Mixing with partially composted yard waste for daily ground cover is fine, but you want to control run-off by avoiding use near a drain or gutter. Thin layers of cover above ground are better than an in-ground pit.

Time. One year is recommended time required for passive composting. This is about the same time period as passive composting for mixed yard waste.

COMPOSTABLE BAGS

Biodegradable is not the same as compostable. Most biodegradable bags require UV to break down, so once you bury them they won’t decompose. Compostable bags, on the other hand, should break down, but they will slow the composting process by blocking oxygen transfer. Testing says most compostable bags will not fully degrade within a year in some piles. Compostable bags tend to be a little thin, so you will want to contain them in something during transport. You should not use them for bucket liners for extended periods for obvious reasons.

BAGS FOR DISPOSAL AS TRASH

Bags bound for the dumpster should be double-bagged and well sealed. Commercial WAG bags are typically 1-2 mil inner and 2-3 mil outer, with a generous allowance for tie-off of the inner bag (electrical cables ties work very well), a zip-lock closure on the outer bag, and an odor barrier or absorbent gel (an aluminized bag is one approach).

There should be no chance of rupture transporting or in the dumpster before compacting. If you don’t want to splurge for a wag bag, or the industrial 1 mil heavy-duty kitchen bag inner bag and 2-3 mil heavy-duty outer waste bag with secure closures is acceptable. For longer trips without a chance for disposal, double-layer bags, like the “double doodie” bag (see “ Controlling Porta Potty Odor , PS September 2018).

SOLID WASTE DISPOSAL

Use only dumpsters handled by machine, not small waste cans or wheeled bins. These provide maximum dilution with other waste and minimum handling. In general, cruisers should dispose of their trash in large bins rather than overfill smaller trash cans.

Outside the 3-mile limit, overboard disposal of both liquid and solid waste is legal and responsible. Nature will take care of it. The best management practices described above apply to inland and coastal waters. As onboard composting becomes more common, failing to follow these common sense steps will wear out the welcome that cruisers before have carefully cultivated.

O ver the past 15 years we’ve tested virtually every aspect of marine sanitation systems, discovering some proven odor-fighting methods and dispelling several myths. For comprehensive coverage of composting heads, download the July 2019 issue from the online archives. Our ebook series “Marine Sanitation,” ( www.practical-sailor.com/product/marine-sanitation-ebook-package ) presents an anthology of our recent research on this topic.

1. The small bag from Cleanwaste fits right inside our portable, taking the mess out of solid waste disposal. We also tested a variety of anti-odor treatments for porta-potties (see “ Controlling Porta Potty Odor ,” PS September 2018).

2. PS has tested a wide range of odor-fighting, cleaning, and maintenance products for boat and RV heads and holding tanks (see “ Stopping Holding Tank Odors ,” Part II, PS December 2012)

3. Even mild acids like vinegar, when overused, can harm joker valves on marine toilets (see “ Clean Potty Overkill ,” PS December 2019).

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Composting head options

When we first bought our Pacific Seacraft, Maria 31, the plumbing systems were in pretty bad shape, the head and black tank being the most serious issue. The previous owner had removed the original black tank and run a hose from the head to a collapsible five-gallon jug in the bilge. It was unsanitary and cringeworthy. Further inspection revealed that the old pump-out line had been semi-abandoned and stuffed into the space between the settee and the hull. The line was old and clogged by decades of dried-out waste. There was less than an inch of clearance and, should someone have been daft enough to try using it for its intended purpose, a crack in the line would have spewed sewage down along the inside of the hull and into the bilge. The whole setup needed to be replaced.

At first we debated installing a traditional marine head. In order to do this, we would need a new black tank and pump-out line. Then we could look forward to all the unpleasantness that comes along with traditional marine heads. Odors can be controlled and minimized with chemical treatments, lots and lots of cleaning solutions and open port lights. But that often means time and effort refocused from enjoying the boat onto odor control. There is also the issue of extra chemicals being pumped into the ocean all in order to avoid nauseating smells. Even marine and ocean-safe cleaners can have an effect on the marine environment. Looking at alternatives Deciding that a traditional marine head was probably not the best bet for us, we started looking at composting heads. There was a lot of conversation online about them but not many out on the water for us to look at. That being the case, research was our best solution. What we found was refreshing. Composting toilets don’t require a black tank or chemical treatments. Instead, the toilet is the storage unit. Since they trap all waste products within the toilet itself, the odor and mess of a traditional head is negated. In addition, they are very easy to install and require little maintenance other than the occasional emptying.

How it works is relatively simple. The composting head is an all-in-one fully functioning unit in which solids and liquids are stored and separated. Liquids are collected in a bottle toward the front of the head. The liquids bottle can be easily removed and poured out, either offshore or down a restroom drain. Solids are collected and composted separately in a drum under the lid of the head. A base of absorbent material like newspaper, husks or wood shavings is typically used as a composting starter. A handle is mounted on the side of the drum that stirs the solid material for aeration and effective decomposition. What little gas there is, is vented from the body of the drum to the exterior of the boat. The only difficulty in using a composting head is muscle control. Liquid and solid deposits need to be made separately for proper containment. No special cleaners or bowl treatments are needed.

The head is mounted to the sole of the boat by a mounting plate and brackets. This plate holds the toilet in place and makes it possible for the drum and liquids bottle to be removed easily when necessary. Since there is no separate black tank and the collection bin is part of the unit, the head does sit a bit taller than a traditional marine head. This height difference must be taken into consideration when contemplating options.

How often the head needs to be emptied depends entirely upon how often it is used. A full-time live-aboard may need to empty the bottle every other day, and the tank every other week. We are seasonal sailors and only need to empty the tank once a season and the bottle every other week. It is not very difficult or time consuming, though taking the head apart for the solids disposal does have a little bit of a learning curve.

Three popular options There are three primary manufacturers of composting marine heads: Air Head, Nature’s Head and C-Head. They all function in basically the same way, but each have a unique design and their own set of quirks.

The Air Head option is perhaps the most popular composting toilet for boats, and it is the one we chose for our own. There are options for a marine or household seat size, which is very convenient considering the limited space of a typical sailboat head. From back to front the entire toilet is 18 inches deep. It stands an overall 20 inches tall. The solids tank sits in the base and is secured to the mounting bracket by two wing nuts. There are also two handles on the side of the tank to make lifting it out easier. The mixing handle sticks out from one side and, when considering placement, the full range of motion must be examined. The liquids bottle is held in place at the front of the unit with tabs that extend up from the mounting bracket. The seat is secured to the solids tank with wing nuts and sealed with a rubber gasket. There is a built-in funnel that directs the liquids away from the solids tank and to the liquids bottle at the front.

To empty the liquids bottle, simply unscrew the two wing nuts and lift the bottle away. The waste can be poured down a restroom drain or overboard if the vessel is far enough out to sea to comply with pump-out laws. To empty the solids tank, first remove the seat and lid by loosening the wing nuts at the front and top of the solids tank. Next, twist and lift the seat up and off the tank then set it aside. Unscrew the two wing nuts holding the tank in place and lift it out. Empty the solid waste into a garbage bag and dispose of it. The Air Head costs $1,029. This is a fully inclusive price and there are no additional pieces that must be purchased. Additional holding tanks and spare bottles can be purchased but are not necessary for initial setup. Visit the Air Head website, www.airheadtoilet.com , for full specs and options.

The Nature’s Head toilet is very similar in design, function and maintenance. The entire unit is 21 inches wide, 19 inches deep and 20 inches tall. There is an option for mixing handles that can reduce the width from 21 inches to 17 inches for conserving space. The unit overall, is a little bigger than the Air Head, but this allows for more stability.

The solids tank is located under the seat and the liquids bottle is separate and at the front of the head. Rather than being secured in place by two wing nuts, the bottle sits in a tray that is integrated into the mounting plate, as does the solids tank. The seat is latched in place over the solids tank and rests atop the liquids bottle, further holding it in place. To empty the head, simply raise the latches on both sides of the seat and lift it away. The bottle can then be pulled out of the holding tray and emptied, as can the solids tank.

For the Nature’s Head, prices start at $925 and can range up to $965, depending on handle and bottle options. There are no extra parts that need to be purchased for the installation and in a single afternoon this head can be set and ready for use. For more info visit Nature’s Head at www.natureshead.net .

The C-Head option is more common for off-the-grid housing and RVs, but they are made with marine applications in mind as well. This unit looks the most like a conventional toilet. The seat is a little larger and there are four different size options available depending on installation needs. All four models are 13.25 inches wide and 18 inches tall. The models range in depth from 18 inches to 15 inches, and have slightly different shapes for bulkhead and corner sets.

As with the previous two models, the C-Head separates the solid and liquid waste. The primary difference is how this is done. The liquids are collected in a non-secured bottle set inside an inset within the housing of the unit. The design does not include a predesigned bottle but suggests using a milk jug or similar bottle. The solids tank is built into the C-Head housing and requires emptying every 10 to 15 uses. To empty, lift the lid and pull the collection tank or bottle out.

The cost of a C-Head starts at $609 and, depending on options, can cost up to roughly $680. This does not include the mounting hardware or the liquids collection bottle. While this option is the least expensive it also requires a bit more effort to get ready. For more info visit C-Head’s website at www.c-head.com .

Composting heads are safe for the environment, easy to use, clean and virtually odorless. There is no pump-out hassle, and disposing of waste is easy. For all these reasons, a composting head made the most sense for us.

Sarah Moore is a mother, writer, adventurer, sailor, backpacker, and avid splasher of puddles. Her work has appeared in Maine Boats Homes & Harbors, Adventure Hats, The Sandy River Review and Doire Press.

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The Boat Galley

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Why did we (A) choose a composting toilet and (B) choose the Nature's Head over others?

Choosing Our Composting Toilet

Published on September 9, 2015 ; last updated on October 31, 2022 by Carolyn Shearlock

One of our big “home improvement” projects has been to change from a traditional wet marine head to a Nature’s Head Composting Toilet (using this link gets you an automatic $25 off at checkout if you buy one).

As we’ve been working on the project and I’ve been posting photos on The Boat Galley’s Facebook page , I keep getting two questions:

Why did we choose to switch to a composting head?
Out of the three brands available (and plenty of DIY plans available online), why’d we choose the Nature’s Head Composting Toilet?

So why did we decide to switch to a composting head? It was a big project, both in terms of work and money, so why’d we do it? In a nutshell, pump outs, stink and time spent repairing the system:

Small holding tank. Our holding tank, at 18 gallons, had to be pumped out every four days. That just didn’t work if we wanted to explore out of the way spots in the Florida Keys (you have to be 12 miles offshore in the Keys to discharge overboard). Those pump-outs aren’t free, either. While there is some cost to the composting medium, it is far less than what we were paying for “extra” pumpouts.
Stink, part 1. The holding tank vent on our boat was positioned so that noxious fumes went straight into the cockpit whenever the head was flushed. That meant that just getting a larger holding tank would not solve all of our problems.
Stink, part 2. There was a certain “head odor” inside the boat, too. Not as bad as in the cockpit, but still noticeable. Replacing the hoses, which were a big culprit, would mean having to remove the holding tank because of where the fittings were. If we were going to have to remove the tank, we wanted it GONE. Composting heads, if built correctly to separate the solids and liquids, don’t smell. Period.
Clogs. Over time, we knew that salt water mixed with urine would cause deposits to build up in the hoses and then lead to clogs. Two problems: we have only one head, so an unusable head due to a clog is very unpleasant, and fixing the problem requires the hoses to be removed and either cleaned out (a very nasty job) or replaced. Again, removing the hoses from the holding tank is a very complicated procedure on this boat. There is nothing to clog up a composting toilet.
Repairs. Joker valves and pumps. It’s not fun to replace a joker valve or rebuild a head pump (yeah, the waste goes through the pump). The parts are expensive, too — over $50 a shot. And when there is a problem, the head is unusable until the repairs are made. Not fun on a boat with only one head. In contrast, there is almost no way that a composting head can be rendered inoperable, particularly if you have a second pee container to use while the first is being emptied. And there is almost zero on-going maintenance (we try to keep the boat as low maintenance as possible so we have time for all the fun stuff cruising offers).
Fewer Thru-Hulls. With a composting head, we could get rid of two below-waterline thru-hulls: the intake for the head and the discharge line. Filling these in is optional in the conversion and took a lot of work (nasty with fiberglass and epoxy), added several weeks to the project (for us; you might be able to do it faster) and cost about $150 in materials alone. We thought it worthwhile from the safety aspect.
Lighter Weight. The composting medium and waste weighs maybe 10 pounds by the time it needs to be changed, compared to say 15 gallons of waste in the holding tank (at roughly 8 pounds per gallon, that’s 120 pounds), plus the weight of the holding tank and the sanitation hoses versus one lightweight ventilation hose. I’m guessing that we’re easily saving 125 pounds — and on a catamaran, every pound is precious!
Can Be Used on the Hard. Okay, this isn’t a major reason, but it’s sort of nice when we’re in the boat yard not to have to trek across the yard to go to the bathroom. Nice not to have go outside even though a thunderstorm is raging or having to get dressed in the middle of the night when “intestinal distress” strikes.

We decided to bite the bullet and deal with the hoses, holding tank and everything else once . The total cost of the project was about $1400, not including yard time (it could be done in the water if you don’t intend to fill in the thru-hulls). The cost will vary depending on the brand/model of composting head chosen, whether you remove and fill the through hulls, any remodeling needed where the head will sit, the vent chosen and what small bits of hardware and wiring are needed.

The time involved will also vary considerably by whether you decide to fill in the thru-hulls and whether anything must be remodeled in the bathroom to accommodate the composting toilet. Once the space was ready, it only took a day to do the actual installation.

So why the Nature’s Head? There are three popular brands of composting toilets for boats: Nature’s Head , Air Head and C-Head. All three are good, solid designs and people seem happy with whichever one they choose.

On some boats, only one brand composting head will fit, so this makes the selection simple. The measurements for each brand are different so if one won’t work, it’s likely that another will — and some are designed to be used in v-shaped bow locations or against a sloping hull. We did not have any special circumstances that limited our choice.

As we were researching, we very quickly decided against the Air Head due to the need to use a coffee filter for solid “deposits.” Some may not be bothered by this, but it just seemed weird to us. Further, several people have said that the coffee filters can get tangled with the agitator in the composting medium. It makes it hard to crank and then they have to be cleared — a nasty job that just goes against many of the reasons we want a composting toilet.

So that left us choosing between the C-Head and the Nature’s Head . The C-Head actually was originally designed for Gemini catamarans, so it seemed like the obvious choice.

But as we talked to friends that had either a C-Head or Nature’s Head, several who had chosen the Nature’s Head gave the same reason for choosing it: the 2.2 gallon urine tank. If you like to entertain aboard — having people over for drinks or dinner — you do not want an overflowing pee bottle in the middle of the party!

That made the decision simple for us. A secondary factor was that we both preferred the way that the Nature’s Head looks.

All that said, I think that we would have been happy with whatever brand we chose. Almost every person I’ve known with a composting head says it’s one of the best upgrades they’ve done . . . regardless of what brand they chose.

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Reader Interactions

Danielle Beaty says

September 9, 2015 at 11:26 am

Great read Carolyn! Thank you for your insights.

Connie Smith says

September 9, 2015 at 11:42 am

What do you do with the urine when at anchor inshore?

The Boat Galley says

September 9, 2015 at 1:09 pm

You can usually find a public restroom. They’re a lot more common than a pumpout boat/station and we can go more than 4 days with two urine containers (4 days was the limit on our pumpout).

September 9, 2015 at 1:13 pm

And I should add that we could get a third urine container if we left that we needed to.

September 9, 2015 at 10:04 pm

Oh, PS — Put the urine bottle in a reasonably heavy duty tote bag and no one will even see it!

Mary Facker says

January 26, 2016 at 8:57 am

Haha great…now I’m going to need a pee bag. Thinking about making this switch in the next couple months!

Frances Liz Fernandez says

September 9, 2015 at 11:58 am

Very interesting!

Pat House says

September 9, 2015 at 12:20 pm

Absolute agree with all you wrote! Used our NH just over two months and only did a partial empty when it got hard to crank. That’s full time use. YMMV. still no odor. 🙂

September 9, 2015 at 7:37 am

Congrats on making the transition to a composting head! We did it last year, and I’m glad.

We chose an Airhead because it was the only large-ish capacity one that would fit, but I’m sure we would have been happy had we chosen one of the competitors, instead.

Although the air head instructions say to use a coffee filter, we don’t bother with it. I think maybe that’s to make clean-up easier if you miss the bomb-bay door when making a deposit. The coffee filter acts as a disposable toilet bowl liner.

But, neither of us have ever “missed” because the bomb-bay door is positioned well. The only time we’ve used a coffee filter is when we’ve been ill.

Also, if you choose to put a full dosage of toilet paper (or a coffee filter) into the composting bin with each use, consider adding some of the septic tank “helper bacteria” you can get in most hardware stores. If you toss in a tablespoon of this stuff every now and then, it seems to make the toilet paper (and presumably coffee filters, also) evolve into compost more quickly, and decrease the frequency of needing to change the composting medium.

SV Chameleon says

May 2, 2017 at 9:05 pm

We also chose the Airhead toilet and have had it for 4 years now. We have never used the coffee filters as they are optional. Another reason we chose the Airhead ove the NH is you do not need to open the solids bin in order to remove the urine bottle for emptying making the process a bit better. So far we have been very happy with our choice.

September 9, 2015 at 7:48 am

Something I would like to eventually do with my boat…but I wonder: Is it always legal to throw the pee overboard? Like, say, in Long Island Sound or other waters with lots of rules. I mean, if a guy peed off the bow, that would be ok… If you have to take the pee bottle to a land toilet to dump, that cuts down on how long you can stay out. A consideration for those of us who are not cruisers, just weekend drifters.

Carolyn Shearlock says

September 9, 2015 at 8:47 am

It all depends on the regulations. In a total “No Discharge Zone,” you can’t dump anything from any type of container into the water. But in many places, it IS okay for pee to go into the water. However, depending on the number of people aboard and the number of urine containers you have, you can go quite a few days before having to find a bathroom where you can dump it. And my experience is that it’s much easier to find a bathroom than a pumpout station!

June 15, 2019 at 8:08 pm

Letter of the law under international treaty and US law, dumping a container by hand is still “discharge” and there is no distinction in the law between urine and feces.

I wondered for a long while how the composting head crowd got around not carrying a bunch of spare bottles or plumbed a urine separation system into a holding tank. I came to the conclusion that the unspoken common practice is that people just dump them overboard wherever (some even in marinas.)

I’m not here to argue the merits of the law nor the ethics of any practices, but that’s what the law says and that’s what you asked.

For what it’s worth, the average adult produces between 800 and 2000 mL of urine per day. Perhaps people will find that bit of trivia useful if they’re opting to hold it aboard until they can dispose of it ashore or outside the no-discharge line.

June 15, 2019 at 8:34 pm

As the owner of a composting toilet and having numerous friends with them, I think that the majority do NOT dump overboard when there is an alternative. And if there is not, as in some foreign countries, they are at least as responsible as folks who jump dump their holding tanks overboard. In most cases, I think composters are better at waiting until offshore.

Edward Tordahl says

September 10, 2015 at 8:52 am

As I mentioned on another post, I had the Natures Head aboard my MacGregor 26X “LAIKA”. It was perfect for that boat. I loved it so much, when I sold LAIKA and purchased my Pearson 323, “SEA HAVEN”, I reinstalled the original Sanipotti, took the Natures Head and installed it on SEA HAVEN. Unfortunately now that SEA HAVEN is on the market, I cannot cost effectively reinstall the old holding system on her so I WILL be purchasing a new Natures head on the next boat! Composting is the way to go nowadays! Suffice to say a lifetime fan!

Nicola says

September 10, 2015 at 1:14 pm

Have been sitting on the sidelines looking at these for ages. Just curious though….how does the pee bottle cope with healing when sailing?

September 11, 2015 at 10:06 am

It will totally depend on the installation. Ours is fore-and-aft, and it appears that the boat would have to get to about a 90 degree angle before pee would start coming out (it’s a small opening in the top). If we get to a 90-degree angle (we have a catamaran), we’re going to have LOTS of problems and the pee bottle would be one of the smaller ones . . .

Beth Lawson says

September 11, 2015 at 9:48 am

We have also been contemplating switching to a composting head. One of my concerns is getting rid of the compost material when you need to. Do you just dump it in the trash bin?

September 11, 2015 at 10:04 am

Everywhere we’ve been, that’s what people are doing. Putting it in a trash bag and then in the trash.

D and Don says

September 15, 2015 at 7:21 am

We went with a Nature’s Head also. A really good decision. Thanks for a very well thought out article that lays it all out for those in the research stage.

Carolyn we hope to see you at the Annapolis Boat Show, will you be there?

D & Don

September 15, 2015 at 8:27 am

Yep! Friday through Sunday — look for our t-shirts with the LARGE “The Boat Galley” on the back. I’ll be at the SAIL magazine booth from 2 to 4 on Saturday, and at the WWS get-together Saturday night.

Jeff Holt says

September 15, 2015 at 8:19 am

We installed a Nature’s Head at the beginning of this season and could not be happier with the outcome. You did a great job summing all the advantages with the conversion. I would add that removing the holding tank and all the hoses frees up a lot of space inside the boat. We essentially gained a whole new storage locker in the main cabin. We did encounter one small flaw in the Nature’s Head design that users should watch out for. The liquid’s trap is not completely separated from the solid’s port. It is possible for toilet paper to make its way into the liquid’s drain chute and block off the urine bottle. Liquids quickly travel to the solid’s container and there is little warning it is happening. Bad smells quickly transpired in our incident and the clean out was extra messy. If you don’t use coffee filters for solids (we don’t) then be vigilant in making sure nothing gets passed into the urine trough.

September 15, 2015 at 8:25 am

Thanks for the info — we don’t put TP into the Nature’s Head so I wouldn’t have known about that. Glad you mentioned it for those who do!

Noreen Perryman says

September 16, 2015 at 6:09 am

Excellent feature tks Caroline. I have a few questions…1 Are these heads becoming cheaper with popularity or have you noticed price hikes as with our exchange rate they very expensive? Can you dispose of TP in the head or what do you do with #2 TP? Is it easy to find the ‘composting matetial’ ? Many thanks NP

September 16, 2015 at 7:07 am

I haven’t seen any change in prices in the past year. They say you can put small amounts of TP in the composting head; we don’t (didn’t with our previous head, either). We have a small lidded trash can that we put all TP in. You can almost always find some composting material — if nothing else, you can use sawdust. All depends on where you are, but just ask other cruisers who are already there and it’s very likely someone will have a composting toilet and know what’s available. And then the next week when someone else comes in and asks, you’re the one to pass the info on!

Amelia says

November 5, 2015 at 2:26 pm

One more composting head thought: if potential purchasers are concerned about the smaller capacity of the C-Head, know that the gallon milk jug urine container can be screw-capped, set aside, and replaced with another free gallon milk jug very quickly and easily. Discolored or scaley ones can be tossed out with nary a second thought. The full jug, if we are outside the 3-mile limit, (admittedly unlikely in our houseboat) gets emptied over the side every night, rinsed, and replaced. If we are in a harbor, we don’t even consider it, We tuck it into a shopping bag and tote it up to the shoreside toilet. One gallon is easier for this old lady to carry inconspicuously than 2.2 gallons! If we are anchored by a nice bit of accessible woodsy wilderness, we are assured that the plants up the hill a ways appreciate the nitrogen and moisture.

Reggie and Barbara says

May 24, 2016 at 12:18 pm

we converted to a Nature’s Head several years ago in our Cal Cruising 36 sailboat and wouldn’t change back.

May 30, 2016 at 11:39 pm

I would love to hear your thoughts on the head now that you have had it for a while?

May 31, 2016 at 8:33 am

Nobody has talked about venting. At first, I planned to install a night and day solar vent for 24 hour venting. However, I decided not to because i did not want to cut a big hole in the boat for the vent and then build the adapters necessary to size down to the vent hose size. We settled on installing a wast tank pump out fitting which was the same size as the vent hose and had a screw in cap for sealing when away from the boat. I would attach pictures if I knew how! And, the small filler size allows for easily choosing a location. For air flow, we use the tiny wafer fan supplied with the Natures’s Head. It draws the tiniest amount of power so draw is not noticed at all. I recommend carrying a spare. A week point is that the wires for that fan are so delicate. I have adhered the fan into its cover with sealant so that the fan will not dangle by the wires when removing the housing to clean the dust filter. Power to this fan is the first breaker turned on when we arrive at the boat. We currently use compressed coir blocks and are happy with that. We bought a 10 pack of the smallest block available and this will probably last us 5 years since we are only on the boat 3-4 months at a time. We tried using peat early on, but I could usually only find bags which contained added fertilizer, etc, and usually only larger bags which were difficult to haul and took up much more storage. Following the rule of never depositing anything into the marine head which has not been chewed first, we do not drop toilet paper into the head. We use zip lock bags for toilet paper, recycling those which came with food in them, such as the bag tortillas come in. It is amazing how many zip style bags you end up with and they might as well be thrown away full of TP as not. Everyone finds a solution with which they are comfortable. That is ours.

September 6, 2017 at 11:30 am

Why dont you plumb in the outlet from the urine separator so that it just goes straight out thru a sea cock instaed of having to empty a jug every couple of days?

September 6, 2017 at 5:04 pm

In a No Discharge Zone in the US, that would be “exceedingly illegal” 🙂

September 7, 2017 at 6:35 am

OK I see. Really enjoying your blog so far and have learnt so much 🙂 I would love to do something similar one day and you are an inspiration. I am 43 yrs old and still working full time and paying a mortgage with 23 years left to run! I don’t have much money. I have an Achilles 24 sailboat which I use at weekends over the summer; it’s moored on the south coast of england. Love it!

Meredith Wright says

January 11, 2018 at 12:48 pm

Stuart…interesting article.

Stuart Dutton says

January 11, 2018 at 1:33 pm

Yep. I really think it my be the way to go.

Kay McDonald says

March 30, 2019 at 1:13 pm

Carolyn, I just finished my NH install “today”, and I started to mount mine fwd/aft as well; however, I went ahead and installed “her” facing the vanity, losing a good inch of entry space. The issue I had with the NH was the hinge that attaches the lid to the tank, with the lid needing a 2″ clearance on the left side. I contacted NH and that sent me a right hand hinge which was very accommodating. with excellent customer service.

Now, for my question to you regarding the NH. How far up do you allow the compost medium to get before you dump it? On my NH, the two holes where the spider crank mixes the poop is about 1/2 way up the holding tank, and it seems to me that it would seep some medium through these holes, if allowed to get up to that point.

What has your experience been? Please advise.

April 2, 2019 at 1:19 pm

It will get hard to crank when it’s time to change it. That’s the best indicator. And that happens before it gets up to the crank.

Downeaster Yachts.com

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Composting Head Review by Ben Okopnik

I spoke with Ben today and got his permission to post this article here. He told me that since this exchange of letters with Natures Head that they have modified the design in some respects to address some of the issues he had brought up here and that they had swapped out his old head for one of the new models and that he is really happy with it. My understanding is that on average the solids tank needs to be emptied about once a month for them “two adults and two children living aboard full time” If they spend much time off the boat or use restroom facilities elsewhere much it extends this time. Ben also mentioned to me that it is vital that you have a working fan or vent to continuously vent the head or it will build up odors. He recommended that I purchase a spare fan to keep on board for the unit.

My Nature’s Head Rant

(If you’re looking for a balancing viewpoint, that comes later. No, seriously; I forwarded this stuff to NH, and they replied) Well worth reading.

Pros and cons: I’ll start by saying that, overall, this is a great option for a marine head; with a little familiarization and practice, it does exactly what it should, exactly as advertised. That’s a huge deal, given the cost of holding tanks, the hassle of finding pumpouts, the ever-present smell associated with typical marine heads, the ability to eliminate two through-hulls, etc. On the other hand, the bits that are badly done really grate; given the price of this unit (about $900 including shipping and an extra urine tank, which I strongly recommend), the time that it’s been around, and the feedback that I’m sure the company has received from the owners, those problems should have been fixed by now. Given how modular and simple this unit is in the first place, those changes would cost either nothing or a few bucks at most, and it offends me all the more for that reason. A list of stuff, good and bad, follows.

WARNING: This is being written by a cranky and opinionated engineer before he’s had his morning coffee. Put on a pair of dark sunshades, zip up your anti-radiation suit, and set your phasers to “stun”.

Here’s the Real Poop

First, kudos to the company for their very friendly and open support. The guy I was talking to (I think it was the owner of NH) was very helpful and knowledgeable, and was willing to… erm… deal with my crap when I told him that I managed to grow some mold on it (there hasn’t been any repeat of that, fortunately.) Heck, he actually asked me to email him pictures so he could figure out whether it’s something they need to deal with or if it’s a one-time problem on my end. This kind of thing makes a big difference when you’re making this big of a change – using a composting head requires thinking differently, so it’s really a change of head space as well as a change of head. His attitude helps a lot, and I consider this to be a big, big hidden plus when you buy a Nature’s Head.
Just as a general design idea, for a big guy like me, making the bowl about 2″ longer would result in much cleaner operation; wiping the back of the bowl after using it wouldn’t be as necessary – but I suppose this would inconvenience the smaller folks (like my wife). Sliding forward about that much is a little less comfortable but makes a huge difference: usually, no wiping at all is necessary (I do use a spray bottle to wash off the traces of urine, as usual.) Much of this is due to the large-enough opening to the main compartment, something other designs haven’t done quite as well. Speaking of other designs – I saw an AirHead the other day, and was completely unimpressed by the quality. The owner of the AirHead, after seeing the NH, really regretted not getting one.
The separation method used by NH works very well: the main compartment stays relatively dry, and the urine goes exactly where it should. Other designs often use a tall riser between the front and the back, or a lip around the main opening; in using the NH, I don’t find them to be necessary.
The NH has a small muffin fan (Evercool EC4010M12C, about $4 online , $12.99 at Radio Shack if you need one right now ) built into the filter housing on one side of the unit. These work great at moving the air over the compost… not so great when the vapors condense in the hose (this happens when you heat the boat in the winter), run back down the hose, and short out the fan. Replacing it involves soldering, which in turn requires unscrewing the power jack in the filter housing; overall, an annoying and unnecessary procedure. It would have been much better for NH to put the fan into the top hose fitting (i.e., the one at the top of the hose, where it passes through the overhead) and avoid the problem.
Sometimes, you see people give up on what they were doing, go off and do something else, and forget about the half-done failed idea. In the NH, this is represented by a long, skewed, badly-glued foam gasket lining the edges of the main compartment. This contributes nothing useful (there’s a high lip that prevents spills molded in) and in fact creates leakage by collecting any drips! Once you get rid of the thing, you’ll actually see decent design under it: there are drain holes for any liquid that does manage to accumulate, which go right into the main compartment. It’s as if a professional started designing this unit, and 90% of the way through, turned it over to high-school students whose main concern was waiting for 4:20 pm to come around. Fortunately, this is easily and quickly remedied.
The opening flap mechanism is very poorly made: it requires disproportionate force to open it, slams loudly, can’t be used at all when sitting on the head (it jams solid), and creaks – loudly – while being used. It’s not like spring-loaded toggled flaps are unusual or difficult, guys… I’ve seen $8 plastic waste baskets that do a great job of it. In addition, the latch handle – another piece of stainless rod – is at just the right height to scratch little kids’ faces (we’ve got a 2-year old curtain climber aboard.) A rubber Superball takes care of that, but… really, the customers shouldn’t have to deal with that kind of stuff.
The compost-turning handle is just awful in every way, design-wise. The skinny SS rod makes it hard to grip and turn (how about a handle to fit over it, huh?) The threaded fitting for the crank, according to NH, is supposed to be locked with LocTite (???); this would allow it to turn in either direction, which is not the case with the unit as assembled. How difficult would it have been to drill the SS sleeve and put in a locking pin instead of threading the rod? Next, the rod simply goes through the walls of the main compartment, with only an SS washer on the inside. Take a wild guess at what happens if you let the compartment get half-way full (which is the height at which the rod comes through) and the compost is less than perfectly dry? Fortunately, the liquid that comes out doesn’t stink – but it’s an unhygienic mess, and not something you really want to deal with. If they had used a simple plastic bushing on the end away from the crank – no need to punch a hole in that compartment wall, people! – and a $2 rotary shaft seal on the crank side, the unit would instantly have almost twice the capacity. It’s this kind of stuff that sends people like me up the wall.
For some reason (perhaps to minimize the amount of hardware on the main compartment, to make it a little less awkward when it’s being dumped?), the latches on the sides are mounted upside down – which means that when you sit down on the head, they lose tension and fall open. A minor thing, but another annoyance. NH suggests bending the bail on the latches to make them tighter; a poor solution, in my opinion, since it results in too much tension when it’s not in use which will eventually result in distorting the plastic. Standing the latches off by 1/4″ and spacing them apart a bit would move the cam-over point further out, letting them stay latched under pressure and keeping the “not in use” tension low.
The hold-down knobs on the sides could definitely stand some improvement: as mounted in my head, one side of the NH is hard to see (as I suspect is the case in many mounting situations), and remounting the head has to be done by feel – and since there’s nothing to tell you whether the slot in the bracket is lined up with the screw hole or not, hunting for it can be a real pain. Allowing the threaded receiver in the body to stick out by a 1/16″ would allow you to feel it “register” in the slot as you aligned it – in fact, it wouldn’t slide past the slot anymore – and would make it much, much easier to remount.

Having said all of that…

…I wouldn’t trade my NH for any other head. It suits my requirements exactly, and I can live with its quirks. No smell, relatively easy to service, and – hell, if I get really annoyed at the above bits, I can spend another $100 or so to fix most of it myself. Someday, when I have the time, maybe… For now, it works for me.

— Ben Okopnik, 2/16/2009

This is a reply to a posting written by Ben Okopnik concerning Nature’s Head. We at Nature’s Head are always evaluating our product and making improvements. We have consulted with physicians, engineers and some cruisers that use our product for their input. Our toilet is used for many applications, not just boats. Our largest sales are for cabins, cottages and homes. Other uses include, military, semi’s, motor homes, campers, and farms. There are reasons we did some things with our design that may raise questions with one application but makes sense when applied to a different use. I will try to address each point or concern of Ben’s. The first point he raised was that he felt the bowl should be 2 inches longer. The bowl and seat area is of commercial size and definitely larger than a marine or Rv toilet. Many applications require a small footprint. He states that the separation of the urine was good. We have recently changed the mold in the urine area to allow the liquid to flow to the bottle much more quickly and to accept larger volume through the spigot. As regards the fan concerns, if you have a problem with the fan, a replacement will be provided at no cost to the customer with the housing ready to bolt on, no soldering for two full years. If it were to fail After two years you can purchase one complete with housing for $20.00. Additionally, the fan is mounted on the toilet for many reasons. One is the convenience to the customer for installation with no unsightly wires to run to the top of a cabin, RV, etc. For applications that use the 110 to 12 volt transformer it is a simple plug and play. Some customers use the toilet as a portable unit, or switch it from their boat to a RV. The fan housing has a gasket so the toilet can be used in a toilet-shower combination. The fan can be switched to either side for customer’s application. Additionally if the fan was at the end of the system it would be exposed directly to the elements which could also shorten its life or lead to it being exposed directly to water. As far as condensation in the vent hose, heating an uninsulated boat, especially with propane will promote condensation. The simple solution would be to allow the vent hose to dip or have a low spot when exiting the toilet. This would allow any water that did occur to accumulate there. Since the hose we use is clear you could see any water that was accumulating and drain it from time to time. The fan is blowing out of the hose so it would not try to draw the water in. The Use of a nicro day-nite solar vent will eliminate the necessity for the built -in fan. As suggestion for heating a boat in the winter; we do this. If you are dockside for the winter use home baseboard heaters; they are efficient and safe, and keep the boat dry. We use the 220 volt, which is available at most marina power boxes, but please consult your marina. There is a company manufacturing 110 volt units that are reportedly as efficient. Regarding the gasket area between the base and bowl, In most boats the toilet is located in with the shower. The gasket is necessary in these applications to make sure that there is not an ingress of water into the main tank if you spray it with a full stream of water. The drain holes are located in the corners rather than under the gasket in order to allow drainage of shower water out of the lip. The lip around the base is there and not on the bowl due to manufacturing concerns. If it were on the bowl, inability to remove the part from the mold would result. So far as the opening flap–or as we call it, trap door. Some earlier ones were harder to open when sitting on the seat. I have one of the earlier one and I weigh 240 lbs and it works fine. We have since tweaked the machining program to make this easier. It is slightly harder than if no one is sitting on the unit. In reference to the eight dollar trash can, I don’t suppose it works at all with a 250 lb person sitting on it. At Natures Head we are always looking for ways to improve on an already great product .As to the trap door arm, Mr. Okopnik has a point. We are currently looking to add a knob that will cover the arm for safety, and that could be easily installed on existing units. We are also considering a handle that will rotate on the crank handle. One of our chief concerns is not adding something that could break under duress in some of the harsher environments that some of our customers and toilets see. The elongated nut which attaches the handle to the agitator was used for a couple of reasons. It facilitates assembly / disassembly by the customer, and it allows for relocation of the handle to the opposite side of the toilet without the difficulty of messing with a drift pin or similar pin. The use of a drift pin would also weaken the shaft area and most likely the pin would fail the first time someone tried to turn it backwards through compost that had dried out too much. Also, some applications such as catamarans, campers, may not have room for a crank handle. In these applications they use the elongated nut with a box ratchet wrench instead of the long handle. We do not see a need for seals around the agitator shaft. Most rubber seals would fail from dirt (compost ) in a short amount of time. The agitator has an industrial plastic flanged bushing and a stainless steel washer on each side inside the compartment. The only way you could have an issue with leakage is if excessive amounts of water have been added or urine has been allowed to enter into the compost area. The peat moss or coconut fiber is to be moist, not wet. No standing liquid should be allowed to accumulate in the compost compartment. One customer had this problem and it was found that their three little boys were peeing in the peat moss with the trap door open. The solids tank is not designed to hold a gallon of urine that is why we separate the urine to the front container. Mr Okopnik also mentions that we should not have drilled through both walls of the solids tank. By drilling through both walls we allow the customer to put the handle on either side of the toilet. It is just a matter of turning the agitator around. In regards to capacity, the unit holds SEVERAL months worth of occasional usage (weekends) or at least a month of full time usage. We even have some customers that remove about 20 percent of the compost and add a little new each week. They have not completely dumped the unit in over a year. Overfilling the solids tank would allow the agitator to sling compost into the upper section creating a mess. A few of the early units did have the latches unlatch when sitting on the unit. We do not have an issue with these now. It was a matter of locating the placement that will work with the various dimensional differences. We have 7 plastic parts that must function together. These parts are created by rotational molding. Every part is a bit different due to thickness and a shrinkage factor of as much as 4% The latches are placed in the present fashion (upside down) to allow for emptying the base without tangling or tearing the plastic bag. Hold down knobs. We feel what we have works, but I understand his point. One concern would be that with the inserts sticking out, it may make the base hang up on the L brackets when removing it for emptying. It would also mean that the bracket and nut would only be tightening up against the insert, possibly allowing the toilet the ability to rock. I suppose there are some minor issues either way. After all that I have stated, we feel we have a good product and will continue to consider suggestions regarding improvements to our product in order to offer the best composting toilet available. Please feel free to call or email any questions or concerns. Regards, Larry Stearns Nature's Head Inc. www.natureshead.net [email protected]

My response follows.

Hi, Larry –

Thank you; I appreciate that. If you don’t mind, I’ll convert this to HTML and add it to my web page as a balancing viewpoint.

In much of what you’ve said, it appears that we got a model that was badly assembled (e.g., the half-glued, crookedly-attached gasket); fortunately, this was not a key factor. Also, the fact that we like to wash the entire unit when we empty it out makes a difference – this is where not having to remove the fan housing, etc. would come in handy.

Our toilet is used for many applications, not just boats. […] There are reasons we did some things with our design that may raise questions with one application but makes sense when applied to a different use.

This is a valid point, and I admit that I had neglected to think of it when writing my critique; however, the fact that I need it to work well for my specific application is also important. If the compromises made for the sake of accomodating variation are so large, then perhaps making several models available would be a better approach.

As regards the fan concerns, if you have a problem with the fan, a replacement will be provided at no cost to the customer with the housing ready to bolt on, no soldering for two full years.

This, I’m afraid, is not made clear anywhere. It was not on any paperwork, and I didn’t find it in searching any of the NH websites. Perhaps a feature this important should be made much more explicit – especially since after-purchase service is so bad with most products these days.

After two years you can purchase one complete with housing for $20.00.

I will definitely be purchasing a spare, since the fan going out becomes an emergency problem very quickly – at least for anyone who has to live in the same space with that head.

Additionally, the fan is mounted on the toilet for many reasons. One is the convenience to the customer for installation with no unsightly wires to run to the top of a cabin, RV, etc.

If you provided an inline fan instead – in other words, essentially the same housing that you now use, except with a hose barb on both sides – then it could be mounted at either end of the hose, and make the head itself completely waterproof (i.e., nothing could be damaged by liquids, showers or otherwise.) The customer could always decide on placement, either right at the head as it is now (e.g., one of the barbs could be removed and the housing bolted to the head), in the middle of the hose, or at the top of it (e.g., if you have a solar-powered vent.) This would allow it to be much more adaptable at minumum cost (i.e., just another flat plate with a barb on it.)

Some customers use the toilet as a portable unit, or switch it from their boat to a RV. The fan housing has a gasket so the toilet can be used in a toilet-shower combination. The fan can be switched to either side for customer’s application.

The change I’ve suggested would still allow all of the above, and would add more flexibility to the system.

Additionally if the fan was at the end of the system it would be exposed directly to the elements which could also shorten its life or lead to it being exposed directly to water.

I did not, of course, intend for the fan to be exposed to weather; I don’t think that anyone would expose the end of the hose to the sky, since that would fill up the head (and drown the fan no matter where it was mounted) during the first rain. On my boat, for example, I have a standpipe on the deck with the hose attached to the inboard end; other people might use a solar-powered vent. The fan would be mounted immediately below the vent, standpipe, deck, or cabin-top for anyone who wanted this kind of functionality.

As far as condensation in the vent hose, heating an uninsulated boat, especially with propane will promote condensation. The simple solution would be to allow the vent hose to dip or have a low spot when exiting the toilet. This would allow any water that did occur to accumulate there.

That’s exactly what I did; however, the capacity of that bend in the hose is very limited – and the water accumulates constantly. The result was a drowned fan. Mounting the fan up high would avoid that completely, and obviate the need for any hose bending or messy draining.

The Use of a nicro day-nite solar vent will eliminate the necessity for the built -in fan.

I agree; however, if the need for a $160 Nicro-Vent can be bypassed by adding a <$1 hose barb, that would be a valuable feature to offer to your customers.

As suggestion for heating a boat in the winter; we do this. If you are dockside for the winter use home baseboard heaters; they are efficient and safe, and keep the boat dry. We use the 220 volt, which is available at most marina power boxes, but please consult your marina. There is a company manufacturing 110 volt units that are reportedly as efficient.

Ah, but we’re not at a marina. Like many people who use your product, we are full-time cruisers. My wife and I both subscribe to a large list of people like ourselves (the LiveAboard list) where questions about heads come up all the time. I’ve been an enthusiastic proponent of the Nature’s Head – which is one of the reasons that I’d like to see it become as good of a product as possible.

Regarding the gasket area between the base and bowl, In most boats the toilet is located in with the shower. The gasket is necessary in these applications to make sure that there is not an ingress of water into the main tank if you spray it with a full stream of water.

Given the poor quality of assembly on our unit, as well as the fact that the gasket was much too long to fit inside the lip (swelling from some sort of chemicals, maybe?), it wouldn’t have done anything useful. Fortunately for us, it wasn’t an issue – we don’t have a combined head/shower.

The drain holes are located in the corners rather than under the gasket in order to allow drainage of shower water out of the lip. The lip around the base is there and not on the bowl due to manufacturing concerns. If it were on the bowl, inability to remove the part from the mold would result.

That lip actually one of the better features of the NH. It helps contain the peat, and the holes are exactly where the should be for most effective drainage.

So far as the opening flap–or as we call it, trap door. Some earlier ones were harder to open when sitting on the seat. I have one of the earlier one and I weigh 240 lbs and it works fine. We have since tweaked the machining program to make this easier. It is slightly harder than if no one is sitting on the unit.

My wife is a rather small woman; if she’s sitting on the head, she cannot open the flap at all. The same is true for me, but I’m bigger. Even without anyone sitting on it, it’s quite difficult to open – and I’m pretty strong. Possibly, there’s a problem with the unit that I have – although I can’t see anything obvious.

In reference to the eight dollar trash can, I don’t suppose it works at all with a 250 lb person sitting on it.

[smile] I did mention the “cranky engineer before the morning coffee” part, yes? Your point is well taken, of course – but those mechanisms work smoothly and well without anyone sitting on them, while the one in the NH does not. That was my point.

At Natures Head we are always looking for ways to improve on an already great product .As to the trap door arm, Mr. Okopnik has a point. We are currently looking to add a knob that will cover the arm for safety, and that could be easily installed on existing units. We are also considering a handle that will rotate on the crank handle. One of our chief concerns is not adding something that could break under duress in some of the harsher environments that some of our customers and toilets see.

A ball made out of the same material that you use for the head, possibly screwed (or pinned with a SS roll pin) onto the end of the handle? It wouldn’t even need to rotate; gripping it loosely while turning (essentially the same thing you have to do with the bare handle now) would be easy and much more comfortable.

The elongated nut which attaches the handle to the agitator was used for a couple of reasons. It facilitates assembly / disassembly by the customer, and it allows for relocation of the handle to the opposite side of the toilet without the difficulty of messing with a drift pin or similar pin. The use of a drift pin would also weaken the shaft area and most likely the pin would fail the first time someone tried to turn it backwards through compost that had dried out too much. Also, some applications such as catamarans, campers, may not have room for a crank handle. In these applications they use the elongated nut with a box ratchet wrench instead of the long handle.

You have a point. Several good ones, actually. Even though it’s a bit of a pain as it is, I withdraw my criticism – although it’s a part of the design that should be revisited with an eye to improvement once in a while.

We do not see a need for seals around the agitator shaft. Most rubber seals would fail from dirt (compost ) in a short amount of time.

Of course; that’s why I didn’t suggest rubber seals. Typically, an industrial liquid-proof bushing/rotary shaft seal would be composed of Teflon and stainless steel – and they’re very inexpensive ($2-3) and available in many sizes. I even provided a link to a source in my original post.

The agitator has an industrial plastic flanged bushing and a stainless steel washer on each side inside the compartment. The only way you could have an issue with leakage is if excessive amounts of water have been added or urine has been allowed to enter into the compost area. The peat moss or coconut fiber is to be moist, not wet.

No, actually if the peat moss is even damp and comes up above the level of the hole, the liquid seeps out. There’s nothing to stop it from leaking out – it’s a hole.

No standing liquid should be allowed to accumulate in the compost compartment. One customer had this problem and it was found that their three little boys were peeing in the peat moss with the trap door open.

Not the situation with us – both of our children are still in diapers.

Mr Okopnik also mentions that we should not have drilled through both walls of the solids tank. By drilling through both walls we allow the customer to put the handle on either side of the toilet. It is just a matter of turning the agitator around.

Again, you have a point in that – although the right solution in that case would be a rotary shaft seal on both sides.

In regards to capacity, the unit holds SEVERAL months worth of occasional usage (weekends) or at least a month of full time usage. We even have some customers that remove about 20 percent of the compost and add a little new each week. They have not completely dumped the unit in over a year.

That’s a really good idea! Perhaps you could create an FAQ on your site containing tips like this one? I’m sure that you have many of them based on your experience, and they would be incredibly useful to any new NH owner. I guarantee you that this would improve customer satisfaction, at least to some degree.

If you need help with that, please feel free to call on me – among other things, I’m a professional web designer .

Overfilling the solids tank would allow the agitator to sling compost into the upper section creating a mess.

True enough – and raising the top higher would be a bad idea for other reasons (the unit is tall enough already!)

A few of the early units did have the latches unlatch when sitting on the unit. We do not have an issue with these now.

But we do. 🙂 Until I get around to fixing it, our NH stays unlatched – it becomes so as soon as one of us sits on it, every time.

The latches are placed in the present fashion (upside down) to allow for emptying the base without tangling or tearing the plastic bag.

Well, I did note that it was only a minor annoyance. If you ever revise the molding plan, adding something like a heavy plastic “loop” to the top and the bottom and providing a pin that slides into those loops, locking the two together would prevent having to mount that set of latches on the NH – and would be much more reliable to boot. If I haven’t made myself very clear, what I mean is something similar to a flat door-bolt arrangement with everything except the bolt being molded as part of the NH unit.

Hold down knobs. We feel what we have works, but I understand his point. One concern would be that with the inserts sticking out, it may make the base hang up on the L brackets when removing it for emptying.

By ‘stick out’, I meant about 1/16″ – just enough to feel it “register”, not enough to hang up on anything.

It would also mean that the bracket and nut would only be tightening up against the insert, possibly allowing the toilet the ability to rock.

Not at all – the insert would fit inside the slot.

After all that I have stated, we feel we have a good product and will continue to consider suggestions regarding improvements to our product in order to offer the best composting toilet available.

You do indeed have a good product; I’m all for it. I’d be glad to see improved as much as possible, though.

Choosing a Composting Marine Toilet

By Rich Johnson
Updated: March 29, 2017

If you’ve ever been aboard a boat with an enclosed head and holding-tank system , you probably know the smell. Trying to explain it away, I’ve heard some boat owners say, “Well, it smells like a boat.” But I’m here to tell you that a boat isn’t supposed to smell like a bad case of low tide.

When we bought our current boat, it was a stinker. Fortunately, we knew what to do about it. In our previous boat, we had installed a composting head, which gave us 10 years of flawless service without a whiff of stench. So, guess what we did to the new-to-us boat? Yup. Removing a holding-tank system is a big job, but we think it’s worth it. Not only is the stench eliminated and there’s no more hauling around wet sewage, but additional stowage space also results from removal of the tank. Finding a pump-out station is no longer a concern. A composting head takes care of all those issues.

Choosing a Composting Head Before beginning this project, make sure your boat will accommodate a composting head . The footprint and bulkhead clearances are the most important considerations. There are two popular composting heads for marine applications. One is Nature’s Head ( natureshead.net ), and the other is Air Head ( airheadtoilet.com ).

In broad technical terms, these units are identical in the way they operate. Solids and liquid are separated at the moment of deposit (that’s you going potty). And that separation is the magic. As long as they are separated, the solids can decompose fairly rapidly and become essentially dirt. Solids are mixed into a bed of peat moss or coconut fiber, and liquid is collected in a separate container for disposal. A small fan moves air through the composting bin to promote friendly microbial activity that transforms the contents into soil. And the air is vented outside, so there is no smell.

There is no plumbing, no valves, no pump, and nothing to break down, clog up or leak. Because there is no possibility for overboard discharge, the unit is U.S. Coast Guard-certified and meets all “no discharge” regulations as a Type III marine head.

The intervals between service depend on owner usage habits. We empty the liquid container about every three or four days when we are on the boat full time for a long cruise. To extend this interval, you can buy additional containers with lids; when one fills, set it aside and replace it with the spare. When you get to a convenient place — say, a marina or launch with a restroom — empty the containers. The solids bin goes for a month or more (60 to 80 uses). The longer you allow the solids to compost, the better. For part-time boat use, we let it go all year before emptying. By then, the solids are nothing but soil that can be added to our flower beds.

The differences between the toilets are primarily design elements intended for service convenience, and each purchaser must decide what is and isn’t important. For our latest installation, we again went with Nature’s Head. Here’s how to do it.

Phase 1: Preparation Begin at your local pump-out station. Suck out everything that’s in the holding tank, then use the water hose to fill the tank about halfway and suck it dry again. Go inside the boat and flush the head, fill it with water, flush it again, and repeat that process several times, which will help clear the plumbing that runs from the toilet to the holding tank. All of this will pay big dividends when you start disassembling the components.

Phase 2: Disassembly We recommend wearing sturdy rubber gloves, safety glasses, and a dust mask or face shield for this, for obvious reasons. As you loosen clamps and disassemble hoses, immediately seal the ends with duct tape to keep anything unpleasant from escaping.

After removing the holding tank and all the hoses, thoroughly clean all the areas where those components were. Leaks are almost inevitable. The problem is, because of the way boat manufacturers route plumbing, leaks are nearly impossible to resolve without dismantling the whole system.

After removing all the components, we used a bleach-and-water solution to disinfect, scrubbing everything multiple times. Then we left the compartments open and placed fans to ventilate and dry the sanitized spaces.

Make sure decommissioned seacocks and the deck pump-out fitting and vent are either removed, and the holes filled with fiberglass, or at least secured in such a way that there’s no chance of them causing water-ingress problems. After closing the seacocks, we installed short lengths of hose on the fittings and then plugged them with tapered wood plugs known as bungs.

Phase 3: Installation The rest of the process of installing a composting head is simple. Locate the spot that allows the head to fit. There are L-brackets that hold the unit to the sole. Mark their positions, drill appropriate holes in the floor, and bolt the brackets in place. That allows you to use mounting knobs to install or remove the head in less than a minute. You read that right. The toilet can be entirely removed from or installed in the boat in less than a minute.

On each side of the compost bin there is a port for attaching a vent hose. The hose and fan can be swapped from one side to the other for installation convenience. Decide how you want to route the vent hose: either up through the deck to a solar vent fan or into an exterior locker (such as the anchor locker). The integral fan can be wired to 12-volt DC for active operation, or you can depend solely on the solar vent fan (not included) to pull air through the chamber, or both.

We opted to wire the fan to the house battery bank that is charged by a pair of solar panels. The 1½-inch diameter vent hose runs to an exterior clamshell vent on the transom. (The vent for the existing holding tank could be refitted and used, but I chose this location for convenience.) The tiny fan draws so little power that there is no risk of depleting the house battery bank, especially with the solar panels keeping things charged.

Operation One nice thing about a composting head is that it’s so simple to use. There are no complicated pump and valve orientation instructions needed for guests. The one rule: On a boat, every visit to the head should be a sit-down occasion. This is because the liquid needs to channel into the small holes in the toilet bowl that lead to the storage tank.

If, on the other hand, you have additional business at hand, activate the handle on the side of the toilet bowl to open the flapper to deposit solids into the compost bin. When finished, close the flapper to seal the compost bin and then turn the crank handle three or four times to mix the compost medium and the solids. We use a spray bottle of water to rinse the bowl with a couple of spritzes. This helps keep it clean and also moistens the composting material.

Toilet paper? You can drop toilet paper into the compost bin, if you wish. It’s best if you use marine or RV paper that is formulated to decompose rapidly. The more paper you “flush” into the compost bin, the faster it will fill up and require emptying.

Maintenance Emptying the compost bin is a snap. Let it go as long as you can still easily turn the mixing lever. The longer, the better — months, if possible. When it comes time to empty the bin, simply remove the upper chamber (toilet bowl part), remove the liquid container, stretch a plastic trash bag over the top of the compost bin, release the mounting knobs at the floor brackets, lift the bin and turn it upside down. All the stuff will tumble into the trash bag. Don’t worry about cleaning out the bin — the old bits of microbe-rich compost stuck inside will jump-start the composting process again. Just put the bin back into the mounting brackets, add fresh peat moss or coconut fiber, and reinstall the upper chamber (bowl) and the liquid container. You’re good to go (so to speak).

You can deposit the trash bag in a dumpster or spread the compost around nonedible plants (not in your vegetable garden). If you’ve waited long enough, the material in the compost bin should look and smell like regular soil.

Clearing the Air Most boaters who have made this conversion state emphatically that they would never go back to a traditional holding-tank system. And we can tell you the same thing. This is one of the best modifications we’ve ever done to a boat.

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Homemade Composting Head

22 Sunday Sep 2013

Posted by shemaya in the boat

≈ 7 Comments

Aboard a boat, there is eventually the question of what to do about bathroom issues. There are a wide variety of possibilities, from low-tech to high – everything from porcelain toilets and plumbing leading to a treated holding tank, to the newspaper and Tupperware system, which more easily fits the space constraints of a kayak. In between are plastic portable toilets with a built-in tank, and, more recently, commercially available composting heads with special seats that divide liquids and solids. Liquids are emptied every day or two, and solids go directly into a container with peat moss or wood shavings or some other loose, dry material, which can be emptied at longer intervals. There is of course the cedar bucket option, but that seems a little tacky close in to a populated shore.

What with various boat projects, and home arrangements related to health issues, I’ve tried just about every system out there, from porcelain to Tupperware. When I started seeing reviews a few years ago of commercially available composting marine heads I was delighted – who knew that you could fit a composting head system (with which I was experienced on shore) into a relatively small boat! Looking at the prices I wasn’t so excited, at $800 or more, and looking at the dimensions and requirements for electrically powered ventilation, I was even less excited. And then the container for the urine didn’t seem well-connected with a small opening, but instead prone to spills in the motion of a small boat on big waves. For a while I was back to the rectangular gray box that river rafters use, which worked fairly well on the Peep Hen.

But for the Chebacco I was inspired to think on this again. Ventilation was still an obstacle – I wanted neither the vent pipe in my vertical space, nor the fan, with its noise and power usage. Mentioning this to the Alaskans, Dave said “oh, my brother and his family have a composting system – it’s in a closet in the cabin, and it has no vent, and there is no terrible smell.” Bingo! It should be mentioned that the brother and family also live in Southeast Alaska. This arrangement might or might not be so workable in a significantly warmer climate, but I like to sail north.

I looked again at the commercial versions, with the idea that one could simply choose to not connect the vent. Still too bulky, and that issue of the possible spillage. While running around the Internet looking into this, I came across an item called the Privy Kit. http://www.ecovita.net/privy.html This is designed for people with outhouses, on land, who wish to divide the liquid and solid materials for composting. Bingo again! About $100, a special toilet bowl for directing materials where you want them to go. Bonus, the drain point for the liquids, which is intended for connection to a hose, is just the right size for an empty gallon water jug, like the kind that spring water or milk comes in. Well-contained, a workable size, and when the jug eventually gets nasty it can be easily replaced. I haven’t had a use for the Styrofoam seat that comes with the Privy Kit, but friends who live with actual outhouses – which can be seriously cold in the winter – are looking forward to giving it a home.

So now we were down to the question of how to put all this together into a boat-friendly system. Additionally, in this boat one goal is to have a head that is “accessible,” meaning manageable from a mobility perspective, in the worst of times. That puts the head right next to my berth, at a height similar to the toilet in the accessible stall of a public bathroom.

As it turns out, that design parameter happens to exactly fit what you end up with if you use a regular 5 gallon bucket for the solids container. Think of that! Additionally, for use in this boat, that height makes a convenient low table, as well as a handy seat in between the berths. It’s always nice to have anything on the boat serve at least three jobs, thoroughly justifying the space it takes up.

In order to make this a low-smell arrangement, especially since it has no vent, it made sense to mimic the commercial version that has a cover for the solids container. And here’s another one of those serendipitous dimensions of the Privy Kit. They may have planned for the liquid connection to fit a gallon jug, but I’m willing to bet that they didn’t actually plan that the opening for solids would neatly go together with a “splash guard” from a medical supply commode!

Somebody else will probably have a much better solution for this, but this one works too: medical supply commodes are those metal frame chairs with a toilet seat that work so well for people who can’t get to a bathroom. They come with a flanged bucket, for use in a bedroom or wherever else, and they come with a flanged plastic sleeve, so that you can put the metal frame over a toilet, as a way to get more height and better handholds. The plastic sleeve then directs everything into the toilet. Which is exactly what we wanted in our five gallon bucket! The inverted commode splash guard, with the larger diameter flanged end down, just fits snugly, at an angle, into a 5 gallon bucket. And, miraculously, the slightly smaller plain edge fits just around the angled outside of the solids opening in the Privy Kit toilet bowl. This takes care of closing off the space between the contents of the bucket and the inside of the head cabinet.

The fussier job, because it needs to fit just right, was making a removable lid for the solids opening in the special toilet bowl. Our prototype was cut from a piece of 1 inch sheet Styrofoam, and covered in plastic wrap, with some duct tape to make a handle on top. That worked just fine, but we have since made a sturdier one, with a foam core and fiberglass/epoxy surface, with a drawer knob for a handle. They both work…

After the interior details were sorted out, it was on to the woodworking phase, making the head cabinet. The cabinet has a door for access to the gallon jug for daily emptying, a piece of plywood cut out into a flat toilet seat with rounded edges, hinged onto the top of the cabinet, and another piece of plywood that fits over the toilet seat making a removable flat “tabletop” surface. That top cover piece has another smaller piece screwed onto its underside, that just barely fits into the toilet seat opening, so there is no slipping when the cover is closed.

Originally it seemed like that top piece should be hinged, and that’s what we did, so there were separate hinges for the toilet seat (for access to the 5 gallon bucket) and for the top. But that made the top very awkward, and unmanageably big, because the toilet seat piece that it was covering is also the cover for the whole area with the 5 gallon bucket and the gallon jug, one in front of the other, inside the cabinet. So in the end that top cover was divided into two pieces: one to be completely removed for use, and the piece toward the back that did not need to be removed, which was screwed down permanently to the back of the toilet seat piece. This has worked much better than the hinged version of the top cover. It is less awkward, and that back piece provides an edge that makes the removable cover more secure when it’s in place. We thought about hinging the cover at that cut, but didn’t want the scratchy hardware on the surface of the table/seat during the head cabinet’s other uses.

I haven’t gone back to check the dimensions of the commercial version of composting head, but I understand better now, why they need to be a bit large. However, building this object into the boat as part of the overall furniture has made it more manageable. As the design was going forward, Theo, who is a highly skilled woodworker, suggested that it would be quite easy to curve the entire side of the cabinet that was going to take up space in the middle of the cabin. What a brilliant idea! You wouldn’t think that this would make all that much difference, but in terms of foot room and space for moving forward and aft in the cabin it has been a wonderful adjustment to the plan. Then after the cabinet was built it was screwed in securely where the long flat side meets the flat side of the port berth.

In use, the procedure is to put a half inch to an inch of peat moss (from the garden store) into the bottom of the empty bucket, and a gallon jug onto the drain where the liquids go. Because of the height of the 5 gallon bucket, a piece of two by something needs to be under the gallon jug to support it. Each time solids go into the bucket, peat moss is added to cover it. Each time liquids go into the jug, a little water is poured into the bowl to rinse it. Seawater works fine for this. Toilet paper goes into a separate container. Theoretically, toilet paper will compost just fine. But unless you fold it or crush it into a very compact little wad, it creates too many air spaces and doesn’t allow peat moss to get where it needs to be, and odors are more of a problem. I’ve found it simpler to just get rid of paper separately. If some paper really needs to go into the compost it helps to fold it up, or to pour on some water afterwards. Stray water in the compost is not a problem, and neither is a small amount of urine. It’s also not a problem if “solids” are not really… additional peat moss will take care of all of those situations.

Occasionally a rather startling white fungi-looking growth starts in the compost, in one spot or another. This seemed alarming at first, but I’ve found that sprinkling peat moss directly on that area makes it go away completely – maybe it dries it out, or maybe the fungi don’t like the pH of the peat moss. At any rate, it doesn’t seem to be the end of the world, and with peat moss applied it’s almost immediately gone.

As for emptying, the gallon jug, with its cover, goes nicely in a canvas bag to carry to a public bathroom, or in open water it can be emptied over the side. In very enclosed harbors – for example Cuttyhunk, or Great Salt Pond at Block Island – I have started a second jug, and stored the first one for emptying all of them after I am out of the harbor. Over the winter we installed a holding tank on AUKLET for exactly this reason. So far it’s just been there for show, but it does mean that the boat is legal for Canada and for the Great Lakes, and if circumstances meant that I would be staying for a week in one of those enclosed harbors, I’d be glad to have the tank.

A note about emptying over the side: last time I checked, within the three-mile limit, as well as on lakes and rivers, it was legal to pee directly off the side of the boat, but not legal to pee into a container and then dump it over the side. We know who this law favors! This seems blatantly unfair, as well as encouraging unsafe behavior. In Alaska, a shocking number of drowned fishermen are later pulled from the water and found with flies undone, suggesting how they came to be falling off the back of the boat in the first place. If it’s legal to pee directly off the boat, it should be legal to safely use a container and then dump it overboard. (End of speech.)

The 5 gallon bucket can be taken care of in a number of ways. I generally empty it every 1 to 3 weeks – it could go longer, but gets heavy. The easiest way to do this is at sea, outside the three-mile limit. Technically, even outside the three-mile limit materials that are legal to dump need to be in small pieces. The following is probably in the category of TMI (“too much information”), but the bucket contents tend to turn into much larger clumps. I have a plastic trowel, the kind sold by camping supply places, for breaking up the contents of the bucket before dumping. The trowel cleans up just fine with toilet paper and seawater, followed by a couple of days of sunshine in the cockpit, which both takes away smells and is an outstanding disinfectant. Far out to sea where nobody is fishing or lobstering I don’t worry about that whole last bit.

Other alternatives for the bucket contents are emptying into a trash bag and putting it into trash on shore, emptying into an outhouse at home or along the way, or emptying into a larger composting container at home for further composting, which when finished looks, and smells, like regular soil, and can be used for flowers and trees, though it’s not recommended for vegetable gardens.

A 30 gallon trash barrel works well for home composting, with screened ventilation (stopping flies) at the top and enough water to be moist but not soaking wet. It’s important that the home compost barrel is metal rather than plastic, because plastic trash barrels nowadays often have pesticide mixed into the plastic. If all those beneficial composting microbes get done in by pesticide, there will be no compost! Surprisingly, the 5 gallon bucket, with a regular lid on it and a bungee for a little more security, is not nasty as far as smells, and is easy to transport home in a regular car without problems. When it’s doable I empty the bucket at sea, but we also keep a home compost barrel and swap out 5 gallon buckets during shore support visits, for areas like Long Island sound or any of the big bays, where one can easily be in more enclosed waters for weeks at a time.

For winter storage it’s a good idea to let the cleaned bucket and other parts be where there is plenty of air movement, like in the garage. Just like the hoses in an ordinary big-boat head system, odors gradually sink into the plastic. But the good news is that given plenty of circulating air, those odors also completely go away. Being an ordinary 5 gallon plastic bucket, it’s also easy to alternate between two, allowing the one that’s not in use to be airing out. This isn’t a big deal, but last year after getting home and thoroughly cleaning the whole thing we reassembled it, ready for spring. Spring came, and after being all closed up for months, we wished we hadn’t done it that way!

The bottom line is that the homemade composting head has worked out really well, in over 10 months of daily use, including the seven months last year and 3+ so far in 2013. It has been far more workable, and lower odor, than any of the other head strategies I’ve tried. Who would’ve thought!

7 thoughts on “Homemade Composting Head”

September 22, 2013 at 6:25 pm

Hey, I’ve been after you to start a blog on the technology of adaptive sailing…. but jeez…. did you have to start from the “bottom up’?

October 12, 2013 at 3:07 pm

Hi Bill, Yes, I know what you mean… That day I had asked myself the question “if I stopped doing this blog tomorrow, what are the topics that really need to be covered?” And this is the one that I have never seen anywhere! Shemaya

April 23, 2019 at 3:28 pm

Really glad I found your blog, I now know exactly how I wil build my composting toilet in my 16′ camping trailer, thanks for the great post.

April 23, 2019 at 3:45 pm

Hi Doug, So glad it’s a help! Wishing you loads of fun on your camping expeditions :-) Shemaya

Pingback: Plans To Build A Wood Compost Bin | Random Ideas

December 15, 2021 at 7:41 am

Are there pictures that include showing the 5 gallon bucket that this article describes? I’m not clear on how all of the description in these paragraphs turn out to actually look, visually

December 15, 2021 at 11:02 am

hi ml, You can see the upper part of the 5 gallon bucket in the first photo– it’s orange. And you can also see the view from the front in the third photo. It also shows up from there because it’s orange. Does that help? It can’t be set up outside of the cabinet, because the cabinet is what supports the blue piece. An identical arrangement is now in the new boat, where I can take a couple more pictures when I’m out there in a few days or so – I expect it’s a little hard to visualize that white sleeve thing. It’s basically a slightly flared cylinder with open ends.

Installing a composting head on board CHRISTMAS.

Thread starter TomY
Start date Mar 20, 2022
Forums for All Owners
Cruising Sailors

Friends of ours did a similar install a few years ago and liked it enough to do a custom install on their second head. It’s a different lifestyle but manageable based on your cruising comfort.

i was never a fan of bathroom humor either. wise to listen to one's mom.

I am looking at doing this same thing with my boat. What was your decision tree for the OGO? dj

dLj said: I am looking at doing this same thing with my boat. What was your decision tree for the OGO? dj Click to expand

And I wondered why you had been so quiet this winter. Awesome.

TomY said: For starters, I talked to friends who were using composting heads. One couple cruising on the other side of the Atlantic and living aboard full time have an Air head. They're happy with it after a few years but they thought the AH (and Natures head, similar) was overkill for part time sailors like us. That plus neither the AH or NH would be an easy fit in our small head. So I talked to friends doing pretty much the same thing as we do who had a C-Head installed for several seasons. They too were very happy with their choice. So I thought I'd go with the C-Head. The C-Head my friends had turned out to be discontinued. It's a stepped version that fits better on raised platforms like we have. Somebody from C-Head was going to check their warehouse to see if they had one left over. That was the last I heard from them. Meanwhile, I had been researching composting toilets and finding other options. At first the OGO turned me off because of the added complexity of the electric auger. But after thinking about it, it began to make sense. I contacted OGO with many questions about build and SS parts etc, and they were very quick to respond. Anything that concerned me has a warranty and parts are easily replaced. I think it is a clever design. Plus they have a nice venting arrangement, a signal light to alert that the liquid tank is 3/4 full, a convenient hatch that closes over the solids when not needed, and a few other details that I think would work better for us. And it's smallest one out there I think with a capacity that will likely make more sense for our sporadic use. Depth is 15", a full 3-4" less than any others I'd looked at. Click to expand

Be sure to post updates after cruising with the OGO this summer. A composting toilet is something that I will be considering down the road. The OGO looks like it will actually fit in my head compartment.

Phil said: Be sure to post updates after cruising with the OGO this summer. A composting toilet is something that I will be considering down the road. The OGO looks like it will actually fit in my head compartment. Click to expand

Tom, I think you will be quite happy with this arrangement. I wish this model had been available when I wanted to switch - between AH, NH and C-Head, none would have fit well in my boat.

dLj said: @TomY I really like the smaller size but I'm concerned as I'm looking to move aboard so my sailing won't be sporadic... I like everything about the OGO but am a bit concerned about the capacity... I checked a few months ago (maybe half a year ago?) and they were saying they were still underdevelopment, but looks like that's now not the case? How long did it take you to get yours after ordering it? dj p.s. This is now a moot point - I just saw they had a special sale going on through March 23rd ( I think) so I just bought this head before the sale is over. I've been looking for some time and this is a very nice looking and seemingly good functioning composting head. I guess I'll find out over time how it works out! Click to expand

SFS said: Tom, I think you will be quite happy with this arrangement. I wish this model had been available when I wanted to switch - between AH, NH and C-Head, none would have fit well in my boat. Click to expand

I hope you post pics when it is installed.

TomY said: Great! I'm no longer alone. I received it quickly, less than a week. Click to expand

TomY said: I was pleased with the actual device. I took it apart and was pleased so far. Parts look easy to change and warranty terms are great. Click to expand

TomY said: This is the second gen. OGO, I think. The big changes are a fluid level sensor that has a signal light. The forerunner had a visual slot to check the level of the liquid tank. I like this idea (sensor) as an overflow wouldn't be fun! I have no idea if these sensors are fool proof, yet. So I'll be wary until the sensor has a track record. Click to expand

TomY said: I'm planning a 1 1/4" stack to run up behind my mast in the head of PVC, to connect a short length of the hose OGO includes. The only real work I have is grinding a glassing in the hole left by the thru hull (it came apart piece by piece!) and running a circuit to the OGO. I'm thinking I'll let the tiny fan run 24/7 as it's draw is so low. Click to expand

jon hansen said: so how do you get the liquids off the boat and where do they get dumped? so how do you get the solids off the boat and where do they get dumped? my 1975 mansfield vac u flush head works so well,, and has since new for sailing with a full crew, why would i want to change? note: zero dumping allowed on the lakes. (even peeing over the side is ticket worthy). pump out stations everywhere. what am i missing? ? Click to expand

That sounds like an interesting toilet. I've had a CHead on my boat for 5 years. It does serve it's purpose but I ended up ventilating mine couple of years ago. Tried several different mediums in the solids tank just seems there's always a smell whenever you lift the access cover prior to use. At least with the AH or NH there's a trap door over the solid portion of the toilet which allows one to urinate without being exposed to the solid bin. Personally wish I had spent the extra $400.00 at that time & purchased the Natures Head. I think in the long run you'll be very happy the chead warehouse didn't get back to you.

TomY said: , I have a leaf compost pile I'll use that will actually compost the waste like the leaves. We'll empty the liquid tank onshore spreading out in trees. Click to expand

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Composting Head vs. Marine Head: Which is Better?

There are many things to consider when choosing a head for your boat.

First and most importantly, a head needs to meet marine pollution regulations .

Secondly, it should be something that you can install and maintain fairly easily. It should be easy and comfortable to use, and it should be reasonably easy to empty and clean.

Other things you should take into consideration when choosing a head include whether you will be living on the boat, how much use the head will get, how many guests you need to accommodate at a time, and the location of your nearest pump-out facility.

So is a marine toilet or a composting toilet the better choice for your boat? Let’s break down the different types of boat toilets, and look at the pros and cons of each.

3 Which Is the Winner?
4 Final Word

Marine Heads

Up until quite recently, marine heads were the de-facto solution for boating toilets. However, they are known to come with a host of difficulties, including leaky parts, the availability (or not) of legal places to dump the waste, and, of course, “head smell.”

There are three common types of marine head: the manual pump head, electric head, and vacu-flush head. They all work slightly differently, but in general, they use either fresh or saltwater to flush waste into a holding tank, which can then be emptied at a pump-out station or offshore.

When they are well-maintained and working correctly, marine heads are great. With a marine head, your waste is “out of sight, out of mind” because it’s stored in a holding tank at the bottom of the boat.

You deal with it at the pump-out station, or you pump it overboard (as long as you are in a place where it’s legal to do so.) Other reasons people like them include:

feels like using a “regular” toilet
non-sailing guests don’t find them gross
pump-out is very easy when you’re offshore

The main issue with marine heads is that they need to be used frequently and maintained properly.

Depending on the type, there are many things that can potentially go wrong with a marine head. All of these things can be costly, time-consuming, and, frankly, gross to fix.

Common complaints about marine heads involve the following:

leaky hoses or tank
waste stuck in hoses
broken pumps
seized 12v motor
some systems use freshwater that could be saved for other purposes
if the pump is manual, guests may not use it correctly

Of all these issues, the odor is listed first because it’s the most common complaint. Marine head odor is so notorious in the boating community that people have written books about how to prevent your head from smelling.

Marine heads smell because the liquid and solid waste get mixed together inside the hoses and holding tank, creating sewage. Sewage often gets stuck in the hoses, valves, and joints on its way to the tank. Then the smell leeches through the hoses and into the rest of the boat.

Marine head systems are also known for being finicky and complicated, with specialized parts that need to be replaced regularly.

Composting Heads

Composting toilets have been around for ages, but they are fairly new to the boating scene. Despite their newness, they’re making waves as a simpler, cleaner, and less smelly solution to traditional marine heads.

That being said, a composting toilet isn’t for everyone. They require you to be much more “hands-on” with your waste and depending on the amount of use the head gets, it might need to be emptied more frequently than a marine toilet.

Composting heads work by separating solid waste and liquid waste in two compartments. The liquid waste tank is a unit on the front of the head that can be removed and dumped overboard. The solids tank is a bucket that gets filled with a composting material like coco coir. Solid waste enters the bucket via a trap door, where it dries out and turns into compost over a period of weeks.

People like composting heads because they are so simple. They require virtually no maintenance and there is very little about them that can break or go wrong.

Composting toilets don’t require hoses, through-hulls, or holding tanks, so they take up less space than a regular marine head. They don’t require any electricity or pumps. They are very easy to maintain and never need servicing or extensive cleaning. Other reasons people like them include:

environmentally friendly (never require chemical treatments)
solids tank can be left full for months without odor
it can handle some things a marine toilet can’t (vomit, feminine products)
never need to worry about finding a pump-out station

A composting toilet is certainly simpler than a marine head, but it’s also very different from a regular toilet.

The liquids tank needs to be emptied frequently, and if solids are not completely composted when it comes time to empty the tank…it can be pretty gross.

Other common complaints include:

more expensive than a marine head
if not properly maintained, the tank can attract flies
not at all like using a regular toilet
non-sailing guests might be grossed out by it
liquids tank is not big enough if you have a large number of guests
if your setup includes a 12v fan, the fan can break

Of all the common complaints about composting toilets, the main issue is the size of the liquids tank. Since it is quite small, it needs to be emptied very frequently or it will overflow. If you live aboard, you’ll find yourself emptying it almost every day.

As far as cost goes, you make up for the initial expense of the composting toilet by not having to purchase replacement parts down the road.

Which Is the Winner?

I should preface this section by saying that I am a true believer in the composting toilet.

I replaced the old marine head on our Morgan 43 with an Airhead three years ago, and I will never go back. I’ve never been on a boat that didn’t smell at least a little bit. Our boat doesn’t smell at all.

Dumping the solids tank is obviously not the most fun I’ve ever had, but it’s not the worst thing in the world either. You can easily put a contractor bag over the open solids tank, and then just turn the tank upside down into the bag and shake out the contents.

You don’t have to do any more than that, because anything that’s left in the tank will continue to compost with the next batch.

So far, we haven’t had issues with guests finding it gross. The other great thing about using it with guests is that the system won’t break if they put things in the toilet that aren’t supposed to be there.

It hasn’t been all sunshine and roses though. We’ve had issues with the 12v fan that pulls odor and moisture out of the solids tank. I’ve also been frustrated by leaks that have happened when I forgot to empty the liquids tank and it overflowed.

A composting head isn’t for everyone. If you’re not comfortable being “hands-on” with your waste once in a while, or you don’t think your guests will be comfortable using it, stick with a marine head. Some of the best options out there include the Jabsco Twist ‘n Lock and Jabsco Compact Electric Toilet.

However, if you’re put off by the smell, or the constant maintenance that a marine head requires, or you’re afraid that something might go wrong that you’re unable or unwilling to fix, a composting head is an excellent solution. Check out the Airhead or Nature’s Head.

Best Marine Composting Toilets For Sailboats

Last Updated by

Daniel Wade

June 15, 2022

Composting toilets are a smart and environmentally-friendly option for marine sanitation.

The best composting toilets for sailboats are the Air Head Mobile toilet, the Nature's Head self-contained toilet, the Separett Villa 9215 toilet, the Sun-Mar Compact electric toilet, and the Pikkuvihrea waterless composting dry toilet.

In this article, we'll review five of the best composting toilets for sailboats. Additionally, we'll cover the legality of composting marine toilets in the United States, along with the fundamentals of self-contained composting sanitation systems.

The information used in this article was sourced directly from composting toilet manufacturers and reference guides for the United States Coast Guard sanitation rules. Additionally, we considered the recommendations of sailors who use and install composting toilets in sailboats.

Table of contents

Are Marine Composting Toilets Different?

Many people wonder if there's a difference between standard composting toilets and marine composting toilets. The answer is complicated, is it depends on the brand and the boat. Many standard composting toilets, which are designed for houses, work perfectly fine on sailboat applications, while others definitely do not.

All of the models on this list can be used on boats, though some require varying levels of modification to be sanitary and to work properly. Positive ventilation is almost always required for a functioning composting toilet, and this can usually be accomplished with a simple low-volume DC fan and a pipe.

Composting Toilet Legality

But what about the Coast Guard? Are there different rules for both with composting toilets? Yes, but in many cases having a composting toilet is actually easier. The Coast Guard's primary concern with toilets is where the waste goes. As long as it doesn't end up in the water where it's not supposed to, then it usually isn't a problem.

That means no dumping or pumping in areas where you're usually not allowed to empty a septic tank. The rules refer to toilets as Marine Sanitation Devices or MSDs. There are different types of MSDS that are subject to different requirements.

According to the EPA, composting toilets are usually considered Type III MSDs , which do not have to be certified by the Coast Guard. They can therefore be used anywhere a Type III MSD can be used as long as they're installed properly and don't discharge waste in unapproved locations.

Requirements vary between boats based on size. Be sure to check Coast Guard, state, and local requirements for your specific boat size and configuration before installing a different toilet.

Choosing the Best Sailboat Composting Toilet

Composting toilets are still fairly new arrivals to the market, so it can be difficult to figure out which one to choose. There are not a whole lot of composting toilets that can be used on boats, given the nature of composting waste in an enclosed environment. That said, there are a few qualifications that make composting toilets ideal for marine use.

First, a marine composting toilet should be entirely self-contained and sanitary. This is especially important in a small enclosed environment like a sailboat head. Additionally, all areas that contain liquid should be leak-proof, and the ventilation pipe should be adaptable for use on a boat.

Given that marine toilets are subject to rolling, they should have sufficient space in the holding tanks to prevent waste from splashing back up the toilet during heeling or rough weather. They should also be compact enough to fit well in a sailboat head.

Best 5 Composting Toilets for Sailboats

We scoured the internet and found five of the best composting toilets for use in sailboats. These toilets come in multiple shapes and sizes, and there's one available for almost every vessel size and configuration.

Though most of these toilets are not specifically designed for marine use, their characteristics make them suitable for adaptation (though some modification may be required).

1. Air Head Mobile Composting Toilet

The Air Head composting toilet is the go-to model for sailboats and powerboats. It's been featured and reviewed and famous publications such as Cruising World, Bluewater Sailing, and Practical Sailor, and it's a favorite of boat builders in many areas.

The simple and self-contained system does away with complex pipes and sanitation tanks without causing unpleasant smells or unsafe conditions. The toilet itself is quite compact, though it hardly resembles typical marine toilets. It features separate holding tanks for liquid and solid waste, which keeps everything efficient and sanitary.

When you purchase the toilet, you purchase your boat's entire sanitation system (more or less), and it's extremely easy to install. All you have to do is hook up the ventilation hose properly, and you'll have a composting head with everything you need to get started.

The airhead composting toilet is one of the most compact units on the market, and it still features all of the typical components found on proper composting toilets. It's safe to use in a rolling and pitching environment, as its self-contained holding tanks are designed to resist leakage.

Overall, the Air Head mobile composting toilet is the best option for sailboats, especially if you're removing an existing head. It's affordable and designed specifically for mobile applications. It's made in the USA with the highest quality materials and most reliable parts.

2. Nature's Head Self Contained Composting Toilet

The Nature's Head self-contained composting toilet is a proven and time-tested product that made a name for itself in tiny houses and off-grid cabins over the years. Its basic design principles are quite similar to the Air Head mobile composting toilet, as this configuration has proven to be quite reliable and pleasant for users.

It's larger than the Air Head composting toilet, but it's still compact enough to fit in most sailboat bathrooms. This model has also seen fairly extensive use on sailboats, even though it's not specifically designed for marine applications.

The chambers are separated, sealed, and lashed together with heavy-duty metal latches. This makes them quite impervious to the rolling and pitching that you're likely to encounter in the cabin of a sailboat. Additionally, the Nature's Head self-contained composting toilet is simple to operate and long-lasting.

Operation is simple, and this composting toilet's holding tanks have a very large capacity. According to the manufacturer, the toilet can be used full-time by two people and emptied only every 4 to 6 weeks. This is great for liveaboards if they don't have to worry about emptying their storage tanks in a place where they're not allowed to.

The design of the Nature's Head composting toilet is modern, which is why it can be so compact and yet highly sanitary. It weighs a mere 28 pounds empty, which means that it will not throw off the balance of your boat when installed.

3. Separett Villa 9215 Composting Toilet

The Separett Villa 9215 composting toilet isn't what you'd traditionally consider a marine toilet, but its design is robust and simple enough to adapt to marine applications. It's a self-contained unit with positive ventilation and separate sealed tanks, which makes it a good candidate for marine use.

It operates on AC or DC power, which is convenient for vessels that are typically wired for 12-volt direct current. Since the unit is entirely self-contained and features a separate gray water tank, it should qualify as a Type III Marine Sanitation Device (MSD).

Solid waste is contained inside of a disposable liner bag, which makes it sanitary and convenient for offloading periodically at the dock. If you have a little more space to work with, the Separett Villa 9215 composting toilet is a good option that's worth considering.

4. Sun-Mar Compact Electric Self-Contained Composting Toilet

The Sun-Mar composting toilet is a self-contained and sanitary unit that makes an excellent option for a boat with a larger head. Though the toilet isn't designed specifically for marine use, Sun-Mar toilets are well-known for use in moving tiny homes and other non-stationary applications.

The Sun-Mar composting toilet is quite advanced, as it includes a thermostatically controlled heater to produce the best quality compost. Additionally, it features electric fans for ventilation that draw minimal power.

The unit is relatively lightweight and entirely self-contained. It's larger than some of the other models on this list, though it's an excellent representation of industry-standard composting toilets. The unit requires a 2" ventilating stack, which is common and usually made of a lightweight and easy to work with material such as PVC or ABS.

5. Pikkuvihrea Waterless Composting Dry Toilet

The Pikkuvihrea waterless composting toilet is the simplest model on our list. It can be adapted for marine applications, though it's probably best suited for houseboats or liveaboard sailboats. The model is entirely self-contained and features very few separate parts.

Unlike most composting toilets, this model comes with virtually everything you need to install and use the toilet. This includes all the necessary hoses, vent pipes, and inserts. The model doesn't have a separate sealed container for liquids, which could be a downside on sailboats (especially in rough water).

Overall, the Pikkuvihrea waterless composting toilet is an affordable and simple composting toilet that will get the job done. If you need a toilet in an extra compartment, or if you're shopping on a budget, the Pikkuvihrea composting toilet should meet the mark. It's lightweight and easy to use and requires no water or drain plumbing.

I've personally had thousands of questions about sailing and sailboats over the years. As I learn and experience sailing, and the community, I share the answers that work and make sense to me, here on Life of Sailing.

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What’s New in Marine Heads

By David Schmidt
Updated: November 14, 2019

While most articles about marine heads start with a humorous anecdote involving a bottle of Purell, I’ll instead begin this ditty with a description of the first truly impressive head that I saw.

Caveat emptor: I have a soft spot in my heart for sailboat racing, so I was justifiably excited when skipper Ken Read (now North Sails’ president) invited me, as a journalist, to sail with the team aboard Avanti , Puma Ocean Racing’s training platform, for an offshore trip ahead of the 2008/2009 Volvo Ocean Race. Under its former ABN Amro II livery, Avanti owned the (then) 24-hour distance record for monohulls (562.96 nautical miles), so there was no question it was blisteringly fast. Stepping belowdecks, I saw that all creature comforts had been stripped for performance, as evidenced by its head, which was situated just forward of the mast. (The galley, of course, was just abaft this same stick.)

And it was just that: a toilet surrounded by a shower curtain. The memorable bit? The seatbelt.

Fortunately, modern heads for cruising boats don’t require this safety feature, however heads are available in a variety of designs and tank options. Here’s a roundup of what’s available on the refit market.

Manual Heads

Operating a manual marine head is one of the most important lessons any landlubber heading to sea needs to learn. At its basic form, a manually operated head consists of a toilet bowl and pedestal, the system’s various valves and hoses, and a holding tank (or tanks) designed to be pumped out via a deck-mounted fitting. To operate, users pump a small amount of water into the bowl, complete their business as normal, and then flush by first flipping a selector switch (typically mounted by the pump), and pumping the handle to drain the bowl. Next, the switch is flipped back, and the sailor continues pumping water through the bowl (system depending, 15 pumps is usually sufficient) to flush the lines.

The water being pumped can be either fresh, salt or a mixture of the two. The mission is then completed by flipping the switch once again and pumping the bowl dry. This also ensures that water can’t continue entering the bowl on its own.

When selecting any of the systems mentioned in this article (with the exception of composting heads) for a refit project, users are highly encouraged to overspec their valves and hoses. “It doesn’t take a rocket scientist to figure out that the smaller the area you try to push anything through, the more likely it is to clog,” says Kim Carrell, Raritan’s controller of sales and marketing. While macerators can help alleviate clogs, especially at the aptly named joker valve, landlubbers should be politely reminded of what should—and should not—enter a marine sanitation device (“MSD” refers to the vessel’s entire sanitation system, not just the toilet itself).

“One of the most entertaining don’ts that we hear is the type of toilet paper that gets used or, in many cases, not used,” Carrell says. “It seems there are a fair number of people who put toilet paper in a separate trash can. We test all of our toilets with the most popular brands of toilet paper, and they pass American National Standards Institute requirements.” Still, “headmares” can be borne of carelessness. “Feminine-hygiene products seem to be one of the worst nightmares, largely because the strings get wrapped around the macerator, rendering it useless,” Carrell says. “In most, using a plunger isn’t a good idea because you ultimately will reverse a joker valve or some other component.”

While the potential for clogging is real, manual heads offer some advantages over other systems in that they are just that: manual. This means that they can still operate with low or no power, and they are fairly simple mechanical systems that can be (and regularly are) field-repaired, provided that the skipper carries spares. It also means that these systems typically have smaller price tags than the fancier sanitation systems, which is also an important consideration. Finally, research and test-flight the different pumping options; some people find certain pump designs (such as foot pedals or back-and-forth handles) easier to use than up-and-down mechanisms.

Electric Heads

As the name implies, electric heads replace manual, pump-action flushing and instead employ a user-friendly push-button system. Also, as mentioned previously, electric heads typically include a macerator that functions in a way that’s similar to a kitchen garbage disposal. The macerators can help to reduce the chances of a clog.

As with an at-home garbage disposal, having access to the macerator’s innards is optimum because blades can fail or, as mentioned, unintended objects can become entangled. Owners are advised to ensure that their macerator blades are of good quality, and to look for designs that give direct access to this potential weak link.

One upgrade option, depending on the design of your current head, is to swap out a manual unit for a similar electric one, which can save a lot of DIY time. Another option, which also depends on the age, condition and design of the existing head, is to retro-add a small electric pump. While this doesn’t add a macerator to the equation, it can greatly simplify operations.

Interestingly, the inverse also sometimes works. “We’re unique in that one of our manual toilets is available with electric operation—but not maceration—and it can be easily converted to manual operation if there is a problem with electric,” Carrell says.

Power consumption and loss of power are, of course, considerations for anyone cruising long distances or on especially lightning-prone waters. While each marine head has different power requirements, typically speaking, most are low-draw systems that are punctuated by brief load bursts of 20 to 30 amps, so careful mariners will ensure that each electric head is installed on its own breaker. Also, some consideration should be given to what happens in the event of a power outage. Larger cruising yachts will likely have multiple heads, so one strategy could be to sail with at least one manual head. Alternatively, buckets are time-honored analog workarounds.

It’s worth noting that while marine-head technology tends to be relatively static compared to, say, electronics innovations, there have been some advances, including sanitation systems that use combinations of both fresh water and brine, as well as those that use radio frequencies. “Our latest Bluetooth smart control allows settings of timing and other parameters on a smartphone, and also collects and displays motor data for troubleshooting,” Carrell says.

Vacuum Heads

No, “vacuum heads” isn’t an obscure reference to Phish fans (Google it—it’s real), but rather a style of head that uses a vacuum flush—rather than a hand pump or electric pump—to empty the bowl’s contents. While designs vary, most vacuums systems include a toilet, a vacuum generator (the vacuum pump and vacuum reservoir), a waste tank (including dockside and overboard discharges) and the various tubing, which can make for a sizable installation. Fortunately for owners of smaller steeds, some systems manage to fit all the components into a single, space-conscious unit.

Flushing operations vary among vacuum heads, with some systems relying on foot-activated levers, while others employ the closing action of the toilet seat’s sealing lid to trigger the flush. Either way, vacuum systems work by creating and maintaining vacuum pressure throughout the system. This energy is released when the system is flushed, instantly clearing the contents of the toilet bowl using fresh water. Depending on the system, some can move waste at a pace of 7 feet per second.

Flushing causes the system’s electric vacuum pump to switch on and run until proper vacuum pressure has been restored. The amount of time required to repressurize the system depends on the length of its run from the toilet bowl to the holding tank, but, generally speaking, a minute does the job.

But for cruisers who are seeking a user-friendly low-odor system, and have sufficient space, amp hours and freshwater supplies, replacing a tired mechanical system with a new vacuum-based marine head can be a wise upgrade.

Illustration courtesy West Marine / Shannon Cain Tumino

Composting Heads

If you’ve ever visited a backcountry outhouse while hiking, you’re likely familiar with its (sometimes) horrors. Fortunately, marine composting heads such as Air Head and Nature’s Head use clever engineering and some basic chemistry, rather than a hole above a hole, to curtail smell while also helping to lower one’s environmental wake.

The design is basic—simple toilet leads to two chambers: one for liquids, and the other for solids (it’s critical that these are bifurcated). Liquid waste can either be dumped overboard if one is sailing more than 3 miles offshore, or it can be stored in the head or in a separate container. (Another option involves evaporation, but this typically requires significant electrical input and is temperature- and humidity-dependent.) Solid waste is stored in a separate chamber that’s first fed with wetted and crumbled peat moss, which can be supplemented as needed. Over time, this chamber heats up to between 140 degrees and 160 degrees Fahrenheit (ballpark), which is hot enough to kill dangerous bacteria.

After using the composting toilet, a crewmember cranks on a handle-type agitator that mixes the solid waste with the chambered peat moss to kick-start the compositing process. A low-voltage fan circulates air in the chamber and helps to keep the compost dry, further bolstering decomposition.

Once the composting process is complete, users are left with an odorless black powder that’s free of dangerous contaminates or bacteria. Legally, it must be brought ashore and disposed of (it’s great for fertilizing flowers and shrubs but not tomatoes or lettuce).

While marine composting heads potentially present a certain gross-out factor for the non-initiated, they come with several significant advantages, starting with the fact that these green-generation systems don’t require through-hull apertures. Furthermore, marine composting heads aren’t reliant on complicated mechanical systems, joker valves or holding tanks, meaning that they’re significantly less likely to clog or require emergency at-sea surgery (cue the Purell).

Marine-composting heads also allow users to skip the pump-out station; however, prospective buyers are gently advised to research how much “user involvement” is required throughout the composting process, and to ensure that this is copasetic with their notions of happy cruising.

In addition to occasionally writing about marine gear, David Schmidt is CW ’s electronics editor.

Vendor Information

Air Head: airheadtoilet.com ; from $1,030

Dometic: dometic.com ; from $300 to $1,500

Jabsco: xylem.com ; from $210 to $1,100

Nature’s Head: natures head.net ; from $960

Purell: purell.com ; from $1

Raritan: raritaneng.com ; from $550 to $2,500

Thetford: thetford.com ; from $210 to $12,000

If you’re a sailor, you’re likely familiar with a certain and rampantly ubiquitous rotten-egg smell that’s commonly associated with marine toilets and their hoses. Despite the temptation to blame the obvious, these odors have nothing to do with the human condition. Fortunately, the fix is easy and doesn’t use environmentally caustic chemicals. “That smell comes from organisms living in the water that die,” Raritan’s Kim Carrell says. “This can be helped by flushing the system with fresh water before leaving the boat, but it’s important to note that the fresh water needs to get into the bowl and all the lines.”

Should odors persist beyond a few solid freshwater rinses, it’s time to dig deeper. “Always consider the age and condition of the existing hose and tanks,” Carrell advises. “We tell people to take a hot rag and rub it on the hose or tank, and if the odor transfers, then this equipment should be replaced.”

Speaking of smells and caustic substances, Carrell warns about the dangers of using at-home products in marine sanitation systems. “A major cause of early head failure is use of common household cleaners,” Carrell says. “Chemicals in these cleaners can attack most plastics and rubber parts.” Instead, cruisers should look for marine-specific products that won’t harm their systems or the fragile marine environment.

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6 Best Marine Composting Toilets: 2024 Complete Guide

head on view of a gray colored marine composting toilet in a boat

You are here because you have a boat that needs a new head or you want info about marine composting toilets. As a buyer, choosing a composting head can be overwhelming, especially if you haven’t owned one. While it might seem like a complicated process, there’s no need to worry, since I reviewed the 5 best marine composting toilets for 2024.

Learn More: How To Choose A Marine Toilet

To help you make an informed decision, I have developed this article in three parts. First, you get a detailed comparison table, next are the in-depth reviews. After, there’s a buyer’s guide for how to choose a composting head for your vessel.

For ease of use I include clickable table of contents to navigate to a specific product or section. Or, scroll down to learn which composting toilet is best for your application.

Outdoors Informed is reader supported. We independently research and rate every product. When you buy through a link on our site, we may earn an affiliate commission. However, our opinions and evaluations are our own. Outdoors Informed does not accept free products from manufacturers. Learn more.

Last Updated: 01/19/2024

Comparison Chart:

Nature's Head Self Contained Composting Toilet with Close Quarters Spider Handle Design

Absolute Best Marine Composting Toilets For Sailboats

Shape: Rectangular
Lower Foot Print: Depth - 19 (+1.5 Rear), Width - 17.75 Inches (+2" Either Side)
Material/Color: Plastic With Stainless Steel Hardware / Granite
Solids Tank Size: 60-80 Uses
Liquid Tank Size: 2.2 Gallons
Total Dimensions: 19" L x 17.75" W x 21.7" H
Weight: 28 Pounds (Empty)
Power Source / Watts: 12 Volt DC Adapter / 3 Watts
Install Method: Floor Mounted
Warranty (years): 5
Compact Foot Print
Anti-Rust Hardware
Separates Solids And Liquids
Easy To Use And Maintain
Fan Draws 1.7 Amps Every 24hrs
Great 5-Year Warranty
Vent Install Instructions Confusing
Complaints Of Weak Vent Fans
Cumbersome Method To Empty Urine Tank

Nature’s Head Compost Toilet (Spider Handle) Review

My pick for the best marine composting toilets in 2024 is a design from two professional sailors. This is the spider handle version of the Nature’s Head.

The first feature boaters love of the Nature’s Head is its capacity. You don’t need to empty it until around 60-80 uses! In real time this equates to a full season of weekend use or around a month for live aboard users. Other great features of this marine head are as follows.

Compact Footprint

The second reason this is an amazing composting head is the small footprint. The toilet base has an actual depth of 19 inches (48.26 cm) and width of 17.75 inches (45.09 cm). As a result, most boats big and small can install this toilet. One thing to keep in mind, you have to mount it on the floor and it needs wood backing underneath.

On the side is the great “spider handle.” This gives extra leverage for composting in tight spaces. The spider handle is best for boats that have little room on the sides of the toilet. Whereas the standard handle is best for people with joint issues. At the time the handle gets too hard to rotate it’s time to empty the solids tank.

Durable Materials

Next, to ensure longevity it uses stainless steel hardware and plastic body construction. Users will appreciate the standard seat height and elongated seat shape. Which means you can sit down without feeling like your feet are dangling or squatting on the floor. Another bonus is the attached seat on the unit. This is great because it means there’s no chance of the toilet seat breaking or shattering in rough waters.

I also like the easy-to-use snap latches on the base that give you access to the solid waste container. This is much easier to use than the thumbscrews found on other products like Airhead. Although some users might not like that you have to lift the container out, instead of sliding it off. On convenient feature is the liquid container comes with a nice carry handle.

For composting with the Nature’s Head, you have two inexpensive options. The solids tank uses either sphagnum peat moss or coco coir, both of which are easy to buy anywhere. In use, single-ply toilet paper is fine for this marine head.

Self-Contained & Odorless

Being a self-contained unit, it uses two containers below the seat to catch the waste. One is for urine and the other for feces, so all composting happens from start to finish inside the unit. To prevent stinky sewage odors, the toilet uses a 12 volt vent fan powered off your boats’ batteries. On the water the fan works well, there was absolutely no odors coming from the solids tank when I used it. However, I do notice a tiny smell from the liquid tank but I fixed this issue with a spray bottle of vinegar/water.

Choose the Nature’s Head with Spider Handle if you want the best composting head on the market. By doing so, you get a hassle-free marine compost head that’s inexpensive, compact and odorless.

Versatile Composting Head For Boats With Holding Tanks

Photo of a white colored Separett Villa 9215 AC/DC Composting Toilet

Shape: Oblong
Lower Foot Print: Depth - 26.5 (+1.1 Rear) Inches, Width - 18 Inches
Material/Color: Polypropylene / White
Solids Tank Size: 6 Gallons
Liquid Tank Size: None- Pipe To Holding Tank
Total Dimensions: 26.5" L x 18 W x 21.6 H
Weight: 36 Pounds (Empty)
Power Source / Watts: 12 Volt DC Adapter & AC Wiring / 2.5 Watts
Install Method: Floor Or Wall Mounted
Warranty (years): 5 - Unit / 3 - Fan
Mimics Household Toilets
Fan Powered 12V DC/110V AC
Wall Or Floor Mounted
Includes Biodegradable Solids Bag
Weight-Activated Solids Trap Door
Good Warranty
No Removable Liquid Tank
Vent Fan Needs Improvement
Solid Tank Trap Door Can Stick Open

Separett Villa 9215 AC/DC Marine Composting Toilets Review

In 2024, the Separett Villa 9215 AC/DC is a great solution for boaters looking to reduce volume in a holding tank. It has a sleek appearance that look modern and clean in any boat. The Villa 9215 is a urine diverting, waterless head with a locking toilet seat. This is great as it prevents the seat from smacking you in rough waves. Capacity for the solids tank comes in a respectable 6 gallon (22.71 l) size.

Unique Composting Design

The unique “handle-less” design of the Villa 9215 appeals to many boaters. In use, it has a solids hatch that opens up as you sit down. Then it rotates the waste container when you rise off the seat. By moving the position of the solids tank, compost has a better chance of drying and breaking down.

Next, to reduce volume in your holding tank, it only allows liquids to flow to it. For solids, it uses an integral composting tank to break down the waste. Thus, you can be on the water for longer between pump-outs.

It’s important to separate the urine from the solids to help the composting process. Urine slows composting because it keeps solids wet and cools them. Optimal composting, needs the solids to be warm and dry.

For ease of use, it comes with 10 compostable bags and one inner waste container with a lid.

Versatile AC/DC Power

Beyond the actual plumbing for the Villa 9215, it also has a feature that no other brand has. The Villa 9215 supports both AC and DC power sources, so you can use it both on and off-grid. AC allows you to use standard marina hookups when onshore. Or use 12-volt DC for offshore with either your vessels’ battery or solar unit.

Effortless Installation

Often installing a watercraft head can become complicated, not so with the Villa 9215. Right out of the box, it takes little time to install this boat head. Out of the box, it’s completely assembled and you can either mount it on the floor or a wall. Be aware though, the toilet base is quite deep at 26.5 inches (67.31 cm). Plus it needs an extra 1.1 inches (2.79 cm) behind it to route the vent piping. Fitting this head might be problematic in smaller boats. Especially due to the heavy weight of the Villa 9215, coming in at a whopping 36 pounds (16.33 kg).

After you mount the actual unit all that’s left is to hook up the hose to the tank and vent pipe. The instructions for the Villa are clear and concise. For venting, it uses a 20 CFM fan that needs 3-inch schedule-40 PVC piped to the outside. All vent components, less the PVC pipe are in the package with this toilet. Although I should note, the fan does get complaints from owners about being too weak.

The Villa 9215 is an interesting option for boaters that still want to use a holding tank. While it’s not a self-contained unit, it’s a good entry-way into the composting world. My only issues with it are it’s large foot print and complaints of the weak vent fan. If you have room for it and can solve the fan output it’s a good performer.

Affordable Compost Head For Pontoon Boats

Lower Foot Print: Depth - 24 Inches , Width - 15.75 Inches
Material/Color: High Density Polyethylene / White
Liquid Tank Size: 1.85 Gallons
Total Dimensions (Inches): 24 L x 15.75 W x 19.8 H
Weight: 11.2 Pounds (Empty)
Install Method: Portable
Warranty (years): 1
50+ Flushes
Easy To Use, Carry And Clean
Double Sealed Drain Valve
Completely Self Contained
Adult Sized Seat And Lid
Tall User Complaints

SereneLife Portable Toilet Review

Finding a compost toilet for a pontoon is near impossible, one solution is a portable head. Yes, this fix is cheating for a best marine composting toilets article. But it’s the only reliable onboard option I have found for pontoon boats. As a big bonus it’s very wallet-friendly!

This is the SereneLife model with button piston pump flush. Even the extra-large waste tank of 5.3 gallons and 3.2 gallon freshwater tank, it’s not a heavy unit. In fact, you can flush 50+ times before having to empty the tank. With four people on the boat, I don’t need to empty it for at least 3 days.

Simple To Use

Families will love how easy it is to use this head, even the kids will have no problem. First, depress the flush pump button to add water to the bowl. After use, pull out the slide valve handle in the front of the unit. Next, once again depress the flush pump to rinse the bowl. To finish, close the slide valve by pushing it in.

Easy To Clean

Likewise, cleaning and emptying are a breeze. Thanks to the rotating no splash waste spout and 3-way flush nozzle design. As an added touch there’s a waste water tank level checker too. The attractive matt finish conceals marks, and allows scrubbing without damage.

Detaching the waste holding tank is simple, via the rust resistant side latches. Both upper and lower tanks are single piece construction, thus no leaking seams.

Durable and heavy duty is how I would describe this boat toilet. Made of high-density polyethylene its rust proof from waves splashing on deck or salt. To protect from leaks or odors it comes with a double-sealed drain valve.

No matter the size of your family, this portable marine head is strong enough to bear the weight of any user. While the company doesn’t list a max weight capacity, I’ve had 350+ pound friends use it with ease. To aid moving the toilet on and off the boat, it comes with a carrying case. Plus a travel toiletry bag to bring all the composting toilet paper you need.

One downside I should mention, tall people complain that its a bit short. Yet you can place it on a sturdy elevated base or bracket to raise it for these users.

These are the best marine composting toilets when an actual compost head is not an option. Particularly if you own a pontoon boat and want a low cost waste solution. For a great price you get a sealed, easy to use and clean toilet. It’s a heavy-duty unit that’s actually super easy to travel with. What more can you ask for!

Easy To Install Toilet For Low Bulkhead Boats

Photo of a white colored Sun-Mar GTG Composting Toilet

Total Dimensions: 24" L x 15.75 W x 19.8 H
Weight: 25 Pounds (Empty)
Power Source / Watts: 12 Volt DC Adapter / 0.6 Watts
Install Method: Wall Mounted
Warranty (years): Info Not Available
Easy to Use
Porta-Potty Or Composting Toilet
Compact Modern Design
Easy Emptying Of Waste
Under 20 Inches In Height
Composting Is Slower
Vague Warranty And No Return Policy
No "Trap Door" For Solids Bin
Hose Not Included
Terrible Instruction Manual

Sun-Mar GTG Composting Head Review

Calling the Sun-Mar GTG a composting toilet is a bit of a stretch. Yes, it has a liquid/solid separator but composting with this unit is as basic as it gets. The solids tank looks like a household waste bin, which you line with a bag and add coco coir to for slow composting. Another option is to leave out the coco fiber and only use the bag as a porta-potty.

I included the GTG as one of the best marine composting toilets for one reason. Its a good option for vessels with low bulkhead room. Think of it as a decent compromise between using a traditional porta-potty and a composting head. But make no mistake this isn’t a feature packed model. I like to think of it as a “rustic experience.”

Value Priced Construction

For design, Sun-Mar sticks with a solid thick resin like material in a one-piece sleek design. The company boasts that it’s a “simple and elegant solution for small spaces.” It’s definitely a good solution for low bulkheads as it measures at 19.8 inches (50.29 cm) in height. The depth and width fall into the middle of the pack of models reviewed.

Weight wise the GTG is the lightest at a mere 25 pounds (11.34 kg), which is great for small boats. As I mentioned before, it’s a basic design to help keep costs low, don’t expect to feel like you are “at-home” on it.

For simplicity the GTG exceeds as it has a one-piece unit with a simple fan and vent hose set-up. However, the Sun-Mar instruction manual is best used as waste-paper as far as I’m concerned. The vent fan is a 12-volt DC with a microscopic power draw of 0.6 watts! Keep in mind, some users complain that the fan wiring is too short and fragile though.

The heavy-duty GTG will support a person up to 300 pounds (136.08 kg). For capacity, it stores liquids up to 1.85 gallons (7 l), and solid sewage up to 6 gallons (22.71 liters).

Is The GTG Compost Head Low Maintenance?

By its proposed design, the GTG should be low maintenance. But in my experience the liquid and solid tanks need improvement. Both tanks sit under the seat but have open tops so liquid and solid sewage can mix. As a result, the composting process gets compromised. Also, if you live in a humid climate this is not the marine head for you. With an open solid waste tank and low powered fan it will never have a chance to dry out and compost.

Picking the GTG is a leap of faith since I couldn’t find any information about a warranty.

If your boat has a low bulkhead that can’t fit a modern composting toilet, then the GTG is a possible solution. It’s better classified as a port-potty with a composting option. Boaters will like it for its simplicity and clean look but will need to except some caveats. The Sun-Mar GTG is for hearty sailors looking to extend the time between emptying.

Runner-Up Best Composting Head For Large Boats

Lower Foot Print: Depth - 19 (+1.5 Rear), Width - 21 Inches (+2" Either Side)
Total Dimensions: 19" L x 21" W x 21.7" H
Super Easy To Install & Clean
Perfect Seat Height
Agitator Handle Very Easy To Rotate
Durable Stainless Steel Hardware
Best-In-Class Customer Service
Slight Odor Issue In Liquid Tank
Larger Footprint Than Others
Poor Instructions For Vent Install

Nature’s Head Compost Toilet (Standard Handle) Review

My runner-up pick in 2024 for best marine composting toilets is the other version of my top pick. This is the Nature’s Head with the standard handle. Choosing this model gets you a robust and dependable compost toilet. One that is simple to install and just works.

The American brand is famous for their marine composting heads. Started by a pair of sailors they have designed a model that fits and functions in a confined space. For peace of mind they offer an awesome 5-year warranty too.

Smooth Agitator Handle

A wider handle means this version won’t be as compact as the “spider-handle” model but it’s not obtrusive. You will need at least 4 inches (10.16 cm) of space on the side the handle is to turn it. The bonus of this handle is most boater feel its much more user-friendly. Rotating the handle tends to be a bit easier and faster, which is better for kids and people with joint issues.

Superior Performance

As I mentioned in my top pick, Nature’s Head tops all compost heads in performance. They are water-free, odor-free, and liquid diverting. The separate sewage tanks are well-secured and the liquid does a great job of diverting. The liquid bin is 2.2 gallons (8.33 l) and the largest of the bunch. To divert the two different types of waste into their bins, you engage a flush handle on the side of the unit.

This model uses 1 gallon (3.79 l) of sphagnum peat moss or coconut fiber. After each addition to the solids bin, turn the agitator handle a few times. This mixes the composting bin to create aerobic action. Like my number one pick, expect a sewage capacity of 60-80 uses before emptying the solid bin.

For venting, this unit ships with 5 feet (1.52 m) of ventilation shaft and a 12-volt DC fan. The fan is economical as it draws a very small amount of power, around 3 watts or 1.7 amps over 24 hours. In use, it does a great job of keeping bad smells out of the living quarters of the boat.

If you want a Nature’s Head compost head, prefer easy agitation and space isn’t an issue this is the model for you. It has excellent performance built with top-in-class materials. Most boaters choose a Nature’s Head and never look back. Still, not convinced? Rest assured it has a return policy and an amazing 5-year warranty too.

Smallest Footprint Electric Compost Toilet

Photo of a white colored OGO Electric Compost Toilet

Lower Foot Print: Depth - 15 Inches , Width - 15 Inches
Solids Tank Size: 25 - 30 Uses
Liquid Tank Size: 2.4 Gallons
Total Dimensions: 16" L x 15 W x 18.5 H
Weight: 28 Pounds
Power Source / Watts: 12 Volt DC Adapter / 5 Amps
Warranty (years): 5 (Plastics) / 1 (Motor)
Push Button Use
Trap Door Separator
Smallest Footprint
Under 19 Inches In Height
Liquid Bottle Leaks
Not As Sturdy Than Others
Lid Pinches
Compost Grinder Unsafe For Kids
Basic Cartoon Instructions

OGO Electric Compost Toilet Toilet Review:

For sailors looking for a modern compact compost toilet this is an option. The small design means it fits almost any room and solves the problem of the old hand crank compost toilets.

It’s super compact at 16 inches long by 15 inches wide by 18.375 inches high. Includes a 5-feet long vent hose that fits a 1-1/4-inch PVC pipe. I appreciate that the inserts for the venting/power and inlet filter are swap-able. Depending on which direction your power source/venting capabilities are coming from.

Boaters will like the simple button to mix the compost medium. As it activates an electric motor spins an agitator bar for 2 minutes to grind the bin contents. When full it has a simple to remove bucket. To clean, you just spray bowl with a mixture of water and white vinegar.

You can flush 25 to 30 times before having to empty the tank. With four people on the boat though, you will need to empty more often than other models. Also the lid has a pinch point, so you have to be careful when closing it. Likewise keep children away from the bowl when the agitator is running.

Urination Features

Never have a I seen a brand so focused on urination features. In fact the OGO urine bottle has a special urine sensor light. It illuminates up when your bottle is almost full, so you never have an overflow problem. For capacity expect the bottle to hold just over 2.4 gallons of liquid.

Next it has a trap door mechanism to separate your liquids from your solids. Although for optimal performance it’s best for men to sit while using the toilet.

This composting head has the smallest install footprint. It’s a good option for boaters looking for a modern looking toilet. Where is looses points in how little solids it holds. But for day trips or overnight boating it is a feature packed

How To Choose Marine Composting Toilets?

Below is a buyers guide for the best marine composting toilets. First I explain what exactly composting toilets are and how they work. Followed by the types, typical installations and general benefits of these types of toilets for your vessel.

What Is A Composting Toilet?

A composting toilet is a type of dry toilet that separates solid and liquid waste using little to no water. It treats human waste via a biological process called composting. This creates an oxygen-rich environment where aerobic organisms break down the waste.

Composting toilets are good solutions for boats without a space for drainage systems. Alternatively, they are a practical option for use in RV camping or for an off-grid cabin.

It’s important to understand that this type is U.S. Coast Guard-certified and meets all “no discharge” regulations as a Type III marine head.

Types Of Composting Toilets

Composting toilets fall into two categories either self-contained or remote compost systems. They further split into two types based on their features, these are:

Simple dry composting toilets

A dry composting toilet uses no water, which is why it’s also called a waterless toilet. This type uses a natural air vent but may use a hand crank agitator to speed up the composting process.

Electric composting toilets

This type is a dry compost toilet but adds the use of an electric fan to enhance the process. A small fan creates continuous airflow through the ventilation line. Helping to dry out the solids tank and evacuate odors. An electric composting toilets is the best option for marine environments. Power for this type can be from a 12 volt system or through a standard 110v onshore supply.

How Does A Composting Toilet Work?

To use a composting toilet a user must sit down to do their business. Liquids get channeled to a separate tank or to a holding dank downstream of the toilet. For solid waste, it gets diverted into its own tank or bin. This bin can be a part of the toilet unit or a separate composting tank away from the toilet.

Inside the bin, waste mixes with a carbon additive. Such as sawdust, coconut coir, or peat moss. This mixing creates air pockets in the human waste to promote aerobic action. It also improves the carbon-to-nitrogen ratio and reduces potential odor.

To compost with aerobic action, the toilet must establish and maintain the following:

The correct moisture level.
A balance of carbon and nitrogen.
The right temperature.

To create these three factor the toilet uses an air vent, flapper and a carbon additive. As well, some brands use a method of agitating the tank such as a hand crank. Another component most marine composting toilets use is an integral 12-volt vent fan. This helps to keep the compost dry and speed up the process.

Once the liquid bin is full, it’s time to empty it. If you are over 3-miles off shore, you can dump over board. For boats inside the 3-mile limit it needs emptying at an approved facility, like a marina.

Inside the solids bin, after the waste transforms it should look and smell like regular soil. Empty the bin into a trash bag and deposit in a dumpster or spread it on non-edible plants.

Install Tips For Composting Marine Heads

Mounting composting marine heads is a simple process as long as you have a spot that allows the toilet to fit. Some will mount on the floor and others can attach to the wall. Most use L-brackets to hold the unit in place.

To start, mark the position of the L-bracket(s). Next, drill the needed holes in the floor, and bolt the brackets down. On most toilets there is a port on the compost bin for attaching a vent hose. Depending on the individual toilet, some may provide the option to attach the hose and fan on either side. Now, determine the route for the vent hose. You have two typical choices, either up through the deck or into an exterior locker, like an anchor locker.

After routing the vent, it’s time to power the vent fan. Most fans connect to a 12-volt DC power source, like a deep cycle battery. Some give you the option of both 12 volt DC and 110 volt AC onshore power. Another solution is to retrofit a solar vent fan to pull air through the vent lines. Sailboat owners who convert away from holding tanks often do this.

To complete the installation, fill the solids bin with the appropriate amount of peat moss or sawdust. That’s it, you’re composting head is ready to use.

Benefits Of Compost Style Toilets For Boats

Are composting toilets worth it? Yes, there are many benefits to owning a composting toilet for your boat. Including:

Marine Composting Head Are Space Savers

Most composting heads are a special design that are a single unit. These units are installation solutions for vessels with limited space. For boats with a holding tank, adding a composting toilet helps to consume less space too. The holding tank will only hold liquid waste which means you don’t need to worry about emptying it out as often.

Composting Toilets Are Waterless

They don’t need any water for flushing waste which will reduce water use onboard. Less water consumption also reduces the amount of wastewater disposal.

Good For The Planet

A marine composting toilet is an eco-sensitive solution to treating human waste. Using natural decomposition to break up solids’ means there are no chemicals involved. Fewer chemicals is great for the environment.

Beyond sitting on the unit, the system is easy. Without the use of valves, plumbing pipes or holding tanks, there isn’t much to worry about. There aren’t any moving parts to fail.

* The only caveat here is using toilet paper with a composting toilet. You have two choices when it comes to toilet paper:

Use single-ply toilet paper as it disintegrates faster in the solids bin.
Have a sealable toilet paper waste-basket to take care of toilet paper. Europeans have done this for years due to their ancient plumbing systems.

Compost Toilets Are Odorless

On many boats with traditional marine plumbing, you might notice a distinct stink. Poor maintained boat plumbing systems are often the culprit. Especially urine caked hoses and holding tanks. With a compost toilet the vent fan takes care of the solids bin while the liquid tank is simple to empty and clean.

Much More Lightweight

Most typical marine heads need holding tanks that can contain around 18 gallons (ca. 68 l) of waste. Whereas a composting toilet might add around 10 pounds (4.54 kg) of weight until it needs emptying. This is a big weight difference which is paramount on small vessels.

Finishing Up The Best Marine Composting Toilets:

All things considered, you can now make an informed choice for the which composting toilet is best for you. Remember to focus on available space, ease of use, venting, and material quality over looks.

Whichever you choose, thanks for allowing Outdoors Informed help you with your research. We love to research, so spend more time doing your business on the water.

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Air Head Composting Toilet (Complete Unit)

Air head advantages, over conventional products, higher capacity means more flexibility in emptying, with no moving parts, fewer breakdowns, superior odor control, over similar products, unique diversion system allows emptying of liquids without opening the solids tank, compact rounded designs fits tighter spaces.

air head vs complicated other head toilets

Air Head vs. Conventional Mobile Systems

More capacity and flexibility in emptying.

“This changes everything because we are no longer tied to the pump out.”

That testimonial came from a Catalina 30 sailboat owner who annually takes a two-week cruise with his family on Lake Michigan. During vacations prior to owning their “Air Head” Composting Toilet, this family would plan their trips from one pump out system to the next, thereby significantly limiting the variety of places to cruise because they had to pump out every few days. With the “Air Head”, they now plan trips without having to pump out since the capacity of the “Air Head” Composting Toilet allows them to go two weeks without emptying. RV owners have discovered the same advantage. “Boon docking” no longer has to be limited to what the black tank can hold. One month of full-time use by two people will yield five gallons of non-offensive smelling, semi-composted material which can be further composted in a plastic garbage can. If you need more capacity, a second tank can be used. The urine, generally considered harmless, can be emptied on the ground in rural places.

No More Smelly Hose or Tank

In standard mobile installations flexible hoses are bound to smell over time due to gas permeability of these hoses. In gravity systems, odors from the holding tank can enter into the living space. Our system makes and processes waste with no offensive odors and uses no permeable hoses. Combined with its active venting system, it simply will not smell up the the living area. How many mobile sanitation systems can make this claim?

Infrequent Solids Emptying

The solids tank may hold enough solid matter for a summer season of weekends. This surprising ability to hold so much in so little space is due to the absence of additional liquids and the product’s ability to break down the matter. For weekend use, the “Air Head” Composting Toilet will contain approximately 80 uses. Full-time use, 60 uses or two people for 1 month.

Simple Means Fewer Breakdowns

When rubber parts in standard mobile heads break due to wear, the unit has to be taken apart, exposing you to contamination as a result of passed sewage—not a pleasant experience. The “Air Head” Composting Toilet is predictable and reliable, and it uses no moving rubber parts. With so many complex systems of your boat, it’s refreshing to have one less thing to worry about. Save the rocket science for the radar.

Peace of Mind

The “Air Head” is self-contained. Everything happens directly beneath the toilet seat. There is a certain peace of mind that goes with not having 20 odd gallons of waste sloshing around in a holding tank under your bed as you try to sleep!

For boaters, no thru-hulls… no holes in your boat!

Easier to Purchase

Confused about the myriad of parts? Valves, pumps, hoses, clamps, toilet, tank, vent ports, etc. are necessary for installation of a holding tank. The “Air Head” Composting Toilet is a complete, all-in-one unit for much less than the cost of a holding tank system. Backed by ONE manufacturer.

Air Head vs. Similar Products

How are we better.

In 2001 we pioneered the use of diversion technology for small living spaces. “Air Head” is the first fully self-contained diversion composting system ever developed. Since that time our legacy is thousands of installations in at least five continents. Early on we focused on the most demanding application: marine. More recently our units can be found in anything from off the grid housing to RV’s. We are particularly proud that our vision has become the choice problem solver for many people who want to live with less environmental impact in tiny houses. We feel that our years of experience and commitment set us beyond those companies who have chosen to mimic our technology. That said, there are many differences that make our design more desirable. These may not be immediately apparent, but our comparison is completely transparent for those who are inclined to analyze objectively.

“Air Head” is the only diversion system that allows emptying of the urine bottle without opening the solids tank.

Our smooth, round Solids Tank is easier to empty and clean.

Our rounded design fits in tight spaces better.

Our opaque bottle with sight glass indicates liquid levels – instead of unnecessarily displaying urine.

When removing liquids bottle, their design exposes the Solids Tank and hinders installation against a wall. Our design eliminates both issues.

Air Head vs. Conventional Composting Toilets

Familiar design.

Since the “Air Head” Composting Toilet is more like a standard home toilet than any other composting toilet, a minimal amount of “potty training” for guests will be necessary. Minor details such as a real toilet seat and lid, “flush lever” location and toilet size, designed to mimic household toilets all contribute to maintaining familiar personal tradition. The ultra-efficient Air Head Composting Toilet does not require users to climb upstairs for use. Whereas non-diverting composting toilets have to be built bigger in size because they are inefficient, requiring extra bulking material to absorb excess liquid. Air Head Composting Toilet is small, yet effective. The Air Head Composting Toilet is a little smaller than the size of a standard home toilet. The ultra-efficient composting chamber handles all of the waste directly beneath the toilet seat. The unit will fit in existing toilet space eliminating the need for remodelling. It will also fit in closets, basements, workshops… anywhere.

The illustrations below represent the approximate sizes and shapes of several leading land-use composting toilets. All of these products lose space-efficiency with their extra internal containers. Air Head Composting Toilet instead uses a thick, rugged, non-permeable solids tank to maximize space savings. With the purchase of extra solids tanks, the system becomes modular, and its capacity significantly increased.

IMAGES

Know-how: Benefits of Installing a Composting Head
Composting Head
Know-how: Benefits of Installing a Composting Head
CompostHead2
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Usage of Nature's Head Composting Toilet
Composting Tip #74
078 Sailing: Our Composting Head
Natures Head Composting Toilet
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COMMENTS

Composting Heads for Cruising Sailboats
Coconut coir comes in dry, compressed blocks that are reconstituted with water, making them easy to store. A single 10-by-4-by-2-inch block will fluff up to about 8 liters of mulch. The Air Head comes with one coconut coir brick, but we have found that using one and a half bricks creates a better starting volume.
Composting Marine Heads
[Editor's note: This is an archive article maintained in our files to provide background information on previous and existing portable "composting" head designs and to offer support for our most recent report on composting heads for boats, also called "desiccating heads," which will appear in the July 2021 issue.
Installing a Composting Head on a Sailboat
A composting toilet works by separating the solid and liquid waste. The solids mix with a moist, peat-like "medium" in the solids container, are periodically agitated and break down over time in an aerobic process (oxygen-rich). Keeping the solids dry (by separating the liquid waste) eliminates smells and accelerates the composting process.
Know-how: Benefits of Installing a Composting Head
It's easy to complicate things on a sailboat. It takes a conscious effort to make things simpler. With that in mind, by going with our new composting head, we were able to remove the following unsavory items from Plaintiff's Rest: 1. A 25gal, 200lb (when full), holding tank.
How to Install a Composting Head on Your Boat
And, of course, it can be legally dumped directly overboard (sans the plastic bags) if your boat happens to be more than 3 miles offshore. Urine diverts into a standard 1-gallon milk jug, to which we added a couple sprays of pet odor neutralizer after each use. This series of photos shows the C-Head, from top: Not in use with primary lid down ...
Thoughts on our Composting Head
Composting Toilets vs. Marine Head & Holding Tank. There are a number of benefits to replacing our marine head with a composting toilet, in addition to simply avoiding sewer water splashing about the boat: PROS. We can go longer between 'removing' our waste. We used to have a 12-gallon holding tank in the v-berth.
Dissecting the Desiccating Head
Separation is accomplished using a separating toilet seat that funnels urine away into a separate container and away from the solid waste (see page 16, "DIY Desiccating Head Options"). Composting systems use a mixer to chop up and blend the solids with the absorbent, making a mess you hope will start to compost.
Composting Head Disposal Options
Composting Head Disposal Options. By. Drew Frye. -. Published: September 20, 2022. 1. A composting toilet puts an end to the pump-out routine, but introduces new challenges in how to dispose of waste. We wouldn't describe ourselves as huge fans of composting/desiccation heads (see " Dissecting the Desiccating Head ," PS July 2021).
Composting head options
The Air Head option is perhaps the most popular composting toilet for boats, and it is the one we chose for our own. There are options for a marine or household seat size, which is very convenient considering the limited space of a typical sailboat head. From back to front the entire toilet is 18 inches deep. It stands an overall 20 inches tall.
What The Head!?
Spring is a time Celene and I start thinking about unwrapping the boat and looking forward to another summer sailing season! However, that comes with a list of boat projects that need to get done. One of the spring boat projects we tackled this past year was replacing our marine head and holding tank with a composting head.
Installing A Natures Head Composting Toilet On A Sailboat
Ever since we started traveling we've used the Natures Head composting toilet. We've had once in our first sailboat, our RV, and now again in our second boat...
Choosing Our Composting Toilet
The parts are expensive, too — over $50 a shot. And when there is a problem, the head is unusable until the repairs are made. Not fun on a boat with only one head. In contrast, there is almost no way that a composting head can be rendered inoperable, particularly if you have a second pee container to use while the first is being emptied.
Composting Head Review by Ben Okopnik
Composting Head Installation; Lavac Installation; Composting Head Review by Ben Okopnik; Replacing the Head Plumbing on DE45 Eolian by Bob Salnick ... sky, since that would fill up the head (and drown the fan no matter where it was mounted) during the first rain. On my boat, for example, I have a standpipe on the deck with the hose attached to ...
Choosing a Composting Marine Toilet
Choosing a Composting Head Before beginning this project, make sure your boat will accommodate a composting head. The footprint and bulkhead clearances are the most important considerations. There are two popular composting heads for marine applications. One is Nature's Head (natureshead.net), and the other is Air Head (airheadtoilet.com).
Marine Toilet, Boat Toilets
Composting Toilets ($800 to $1,000) A relative newcomer to the marine-toilet marketplace, composting heads are starting to make their way onto more boats. Such composting heads as the Air Head ($1,030) or Nature's Head ($925) offer a major benefit over other systems in that they require no through-hulls.
Homemade Composting Head
Additionally, in this boat one goal is to have a head that is "accessible," meaning manageable from a mobility perspective, in the worst of times. That puts the head right next to my berth, at a height similar to the toilet in the accessible stall of a public bathroom. ... The bottom line is that the homemade composting head has worked out ...
Installing a composting head on board CHRISTMAS.
To bring that head up to current standards, it would be a lot of work: find a place for a holding tank, run all the piping, plus deck discharge fittings, the whole thing. That one was a no brainer to just update to a composting head. My aft head is a modern electric head with full holding tank and all the correct installation.
Composting Head vs. Marine Head: Which is Better?
That being said, a composting toilet isn't for everyone. They require you to be much more "hands-on" with your waste and depending on the amount of use the head gets, it might need to be emptied more frequently than a marine toilet. Composting heads work by separating solid waste and liquid waste in two compartments.
Nature's Head and Venting
Join Date: Apr 2013. Location: St Thomas, USVI. Posts: 542. Nature's Head and Venting. We've decided to rip out the smelly old jabsco and holding tank in favor of a composting head. So a question about venting unique to our situation. I'd rather not drill a new hole in our deck for the vent tube, so I'm wondering if I can use the old pump out hole.
Best Marine Composting Toilets For Sailboats
June 15, 2022. Composting toilets are a smart and environmentally-friendly option for marine sanitation. The best composting toilets for sailboats are the Air Head Mobile toilet, the Nature's Head self-contained toilet, the Separett Villa 9215 toilet, the Sun-Mar Compact electric toilet, and the Pikkuvihrea waterless composting dry toilet.
What's New in Marine Heads
But for cruisers who are seeking a user-friendly low-odor system, and have sufficient space, amp hours and freshwater supplies, replacing a tired mechanical system with a new vacuum-based marine head can be a wise upgrade. 1. Raw water to head 2. Marine head 3. Discharge to tank 4.
6 Best Marine Composting Toilets To Buy In 2024
Separett Villa 9215 AC/DC Marine Composting Toilets Review. In 2024, the Separett Villa 9215 AC/DC is a great solution for boaters looking to reduce volume in a holding tank. It has a sleek appearance that look modern and clean in any boat. The Villa 9215 is a urine diverting, waterless head with a locking toilet seat.
Air Head Composting Toilet
That testimonial came from a Catalina 30 sailboat owner who annually takes a two-week cruise with his family on Lake Michigan. During vacations prior to owning their "Air Head" Composting Toilet, this family would plan their trips from one pump out system to the next, thereby significantly limiting the variety of places to cruise because ...