jim brown trimaran plans

Designed by John Marples and Jim Brown

John Marples and Jim Brown have produced designs of successful sail and power craft for over 40 years using conventional materials and cutting-edge design to produce vessels that are stronger, more seaworthy, and more practical to build than ever before. Ease of handling, longevity, utility, operating cost, investment value, and speed are all essential components of what we term Total Performance in pleasure or commercial craft design.

These vessel designs are straight-forward, easy to build, wood and epoxy, using various construction methods for multihulls and dinghies from 7 to 64 feet. Our portfolio of designs includes trimarans and catamarans, sail and power, pleasure and USCG certified commercial vessels.

The site is under construction at the moment but soon you\'ll be able to view the Design Portfolio of our entire design line or purchase Study Plans for individual vessels from this web site. Call today for a personal consultation. We look forward to assisting you with your boatbuilding project. In addition to plans, we offer design consultation and USCG certification services for wood and fiberglass vessels, power or sail, with multihulls of all types, as a specialty.

Over the last 20 years, John has helped the owners of 30 multihulled vessels certify their boats with the USCG to carry passengers for hire. These vessels,ranging from 32\' to 64\' long, were approved to carry between 16 and 149 passengers. Some owners were building a new boat and called John before they started construction. John reviewed their plans and then modified them to include the necessary components required for certification. Once John submitted the plans and the USCG approved them, he continued working as a liaison between the owner, builder, and Coast Guard until the finished boat passed its Coast Guard inspection. Other owners had an existing boat that required modification for CG approval. Again, John made the necessary design changes and submitted them for approval. He worked with the owner and builder to help minimize the cost of making structural changes to the vessel. John worked as liaison throughout the reconstruction until the certification process was complete. You can find out more about USCG certification elsewhere on our website.

Contact John at marplesmarine[AT]gmail[DOT]com or call him Monday through Friday from 9 a.m. to 5 p.m. (Eastern Time Zone) at 207–326–8096.

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October 26, 2020

An Interview With Multihull Pioneer - Jim Brown

Jim Brown got his start designing and building sailing trimarans from friend and mentor, Arthur Piver, near Sausilito, CA in the late 1950's. Jim's foray into his career as 'trimaran test pilot' is well documented in his entertaining book, 'Among The Multihulls: Volume I'. In this Dream 10X podcast episode, however, we learn more about the story of Jim's early childhood leading up to the story in this book. I think this as-of-yet untold story of his early youth is just as fantastic and entertaining as his book!

The real skill in pioneering, as in business and life, is survival. Jim Brown, Among The Multihulls: Volume I, Pg 46

Finding Your Passion

One thing I wish I could ‘teach’ my own kids is how to find your passion in life and how to follow it. Unfortunately, I’m not sure that is something that can be taught, but it can certainly be felt and even witnessed in other people’s lives. One case in point is the life of Jim Brown. It’s not hard to look back over Jim’s life to see how his simple pursuit of his singular passion for boats and the ocean took him on extraordinary life adventures. When he essentially flunked-out of college mostly due to his poor eyesight, he decided to continue pursuing his passion for boats by heading off to Miami to jump on the schooner Janeen, which in turn led to events that positively impacted the arc of his professional and personal life.

In other words, he didn’t know what his life held for him when he dropped out of college, but he knew he had an interest in boats and the ocean so he jumped in (or on a schooner) with ‘boat’ feet not knowing where things would lead him.

One of my favorite movie quotes is from the movie ‘Cast Away:’

And I know what I have to do now. I gotta keep breathing. Because tomorrow the sun will rise. Who knows what the tide could bring? Chuck Noland, Cast Away

It would seem that finding your life’s passion can be rather simple. Take action and keep moving in some direction - any direction. You never know what the tide will bring!

Continuous Learning

Jim exemplifies the idea of continuous learning throughout life. Since he was a college drop-out, it is evident to see that his genius and knowledge is not a product of an institution of ‘higher’ education. In fact, it would seem to me that Jim had an adequate knowledge toolkit available to him since childhood: a burning curiosity about things, an ability to teach himself answers to his own curiosities, and simple naivety in not knowing that he could not do things others might have said were impossible. Jim’s child-like curiosity and naivety in all things nautical have allowed him to constantly innovate in his profession throughout his fascinating career, and have afforded him the relative luxury of hanging-out in metaphorical littoral zones between modern western ‘civilization’ and the ‘wilder,’ less civilized, parts of the world.

A Closer Look Into Jim’s Life Adventures

The following video contains a slide-show narrated by Jim Brown himself, which he did just for us at Dream 10X!

Relevant Links

• Jim’s G-Man Father, Ralph
• Curtis JN-4 Jenny Biplane
• Jim’s Outrig Media Project
• Jim Brown and John Marples Trimaran Plans
• Jim’s Son Russell Brown’s Website
• My Favorite Video Of A Seaclipper 20
• WindRider Trimarans
• Chesapeake Light Craft
• Race To Alaska (R2AK)
• The WoodenBoat School

James Caple 2020-10-12 BLOG podcast sailing trimaran multihull catamaran arthur piver jim brown walt glaser woody brown dick newick Chesapeake Bay Virginia environment ecology marine architecture innovation design adventure microadventure

Dialogue & Discussion

4,000 years in the making

Unforgettable sea stories, the sights and sounds of history, welcome to beyond mainstream, take 4,000-year-old technology, add a group of 1950s radical sailors and genius engineers and you get a movement that defied sailing convention and redefined freedom. sailor, marine designer, adventurer and author jim brown has been on a 70-year high seas odyssey capturing the characters and culture of the modern multihull movement. the beyond mainstream project is cataloging and gathering jim’s vast library of photos, videos, articles and podcasts into an accessible form to share with all. and, coming soon, a documentary dedicated to this movement and the amazing cast of characters behind it..

Join Jim’s Friends And Help Share The Stories

This website will continue to catalog and organize Jim Brown’s and Scott Brown’s vast library of photos, videos, articles and podcasts, and also add new material as Jim remains a prolific storyteller! Additionally, work has begun on a documentary with a release date planned for late-2024. Experienced filmmakers Michael Frierson and Kevin Wells are turning hundreds of hours of interviews and archival footage into a 90-minute feature film documenting the development of multihulls and the amazing cast of characters behind the revolution!

You’re signed up!

Thank you for joining Friends of Jim Brown in our mission to organize, catalog, and share the amazing story of multihulls and one of the movement’s renowned pioneers.

I’ve known and admired Jim for a long time. This is why I and a couple of others in his circle have come together to pursue this project. If you are interested in supporting Beyond Mainstream or have questions, I’d be happy to talk. Send me an email and I’ll get right back to you.

And thanks again,

Andy Zimmerman

Email Andy at [email protected]

Get Jim's Books

"During a particular period in the 20th century a bunch of non-traditional engineers and tinkerers started thinking quite differently about the traditional craft of boatbuilding, and about the conventions of society. These guys jumped right out of the western tradition, grabbed some principles from a totally different genus (aircraft) and invented a hybrid vessel with hybrid vigor. I’ll never have the wherewithal to own a J-boat, a downeaster, or a Gloucester fishing schooner, but I can own a trimaran, because it was designed for people like me to build, own and sail. That’s a pretty amazing concept in this world of specialized manufacturing, oven-baked carbon fiber race boats and the growth of the indentured class."

"Part memoir, part adventure story, part travelogue, totally compelling.”

— From reviews of Jim’s memoir, Among the Multihulls

Friends of Jim would like to give special thanks to Scott Brown. Without his help and support, none of this would be possible.

© 2024 Friends of Jim Brown

Professional BoatBuilder Magazine

The voice of multihull pioneer jim brown.

By Dan Spurr , Jul 10, 2017

No, the famed multihull designer and builder won’t be appearing on the popular television show anytime soon, but you can hear him tell seafaring tales on a growing series of recorded podcasts and videos.

By way of background on Jim Brown, he gained attention in the 1950s by building an Arthur Piver–designed trimaran and cruising it extensively. This formed the basis of his series of Searunner trimaran designs, which were intended for home construction in plywood. To advance his affection for multihulls he wrote several books, including The Case for the Cruising Trimaran and Among the Multihulls . He also helped develop the Constant Camber method of hull construction, in which identical plywood panels are formed over a mold by gluing precut strips of wood veneer, similar to cold-molding. Brown exported his methods to developing countries to help fishermen build simple working watercraft. So you might say he’s seen a thing or two. Search the PBB online index for articles with his byline, the most recent of which was the Parting Shot “Foil Train Coming,” in PBB No. 156, where he shares his enthusiasm for Peter Johnstone’s large foiling G4 catamaran.

Jim Brown aboard the  Scrimshaw . This screenshot was taken from a video he narrates about living aboard his famous Searunner trimaran.

The most recent of Brown’s 30 podcasts, posted on outrigmedia.com is titled “Stranded on a What?!” The 28-minute yarn recounts a 1981 cruise aboard his and his wife Jo Anna’s trimaran Scrimshaw , in which they decide to cruise from their Virginia home to Nova Scotia. The guitar prelude and Brown’s folkie talking style reminds one of preambles by folksinger Pete Seeger. Serious fog is encountered off the coast. Wouldn’t you know, there’s a large commercial fishing fleet working the banks. And the crashing waves are indistinguishable from the sound of breakers on the treacherous rock ledges. After three days of playing cat and mouse with steel hulls, they decide to head offshore rather than make landfall. If you’ve ever been off the New England coast in fog and attempted to ascertain your position with a radio direction finder (RDF), you’ll appreciate his account of fumbling with that thankfully now-obsolete device. Before GPS, that’s all we had. Eventually Jim and Jo Anna make an anchorage in St. Margarets Bay, whereupon they meet an unusual cast of characters living in a shanty while building what’s described as a castle for the owner. As they get to know one another, of course they tell sea stories, one of which is about a man stranded on a dead whale, his boots sinking into “stinking, decomposing blubber.” Yes, you read that right.

Besides outrigmedia.com , the source of these podcasts and a place to buy books and CDs about Jim Brown and other multihullers, check out Brown’s own website at www.outrig.org , dedicated to preserving the history of mul tihulls.

Brown’s growing multimedia output also includes videos that he narrates on multihull pioneers, and a series about sailing and living aboard his famous Searunner trimaran Scrimshaw, such as the one posted above. To see a list of more videos, visit http://www.outrig.org/outrig.org/Videos.html .

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4,000 years in the making

Unforgettable sea stories, the sights and sounds of history, welcome to beyond mainstream, take 4,000-year-old technology, add a group of 1950s radical sailors and genius engineers and you get a movement that defied sailing convention and redefined freedom. sailor, marine designer, adventurer and author jim brown has been on a 70-year high seas odyssey capturing the characters and culture of the modern multihull movement. the beyond mainstream project is cataloging and gathering jim’s vast library of photos, videos, articles and podcasts into an accessible form to share with all. and, coming soon, a documentary dedicated to this movement and the amazing cast of characters behind it..

Join Jim’s Friends And Help Share The Stories

This website will continue to catalog and organize Jim Brown’s and Scott Brown’s vast library of photos, videos, articles and podcasts, and also add new material as Jim remains a prolific storyteller! Additionally, work has begun on a documentary with a release date planned for late-2024. Experienced filmmakers Michael Frierson and Kevin Wells are turning hundreds of hours of interviews and archival footage into a 90-minute feature film documenting the development of multihulls and the amazing cast of characters behind the revolution!

You’re signed up!

Thank you for joining Friends of Jim Brown in our mission to organize, catalog, and share the amazing story of multihulls and one of the movement’s renowned pioneers.

I’ve known and admired Jim for a long time. This is why I and a couple of others in his circle have come together to pursue this project. If you are interested in supporting Beyond Mainstream or have questions, I’d be happy to talk. Send me an email and I’ll get right back to you.

And thanks again,

Andy Zimmerman

Email Andy at [email protected]

Get Jim's Books

"During a particular period in the 20th century a bunch of non-traditional engineers and tinkerers started thinking quite differently about the traditional craft of boatbuilding, and about the conventions of society. These guys jumped right out of the western tradition, grabbed some principles from a totally different genus (aircraft) and invented a hybrid vessel with hybrid vigor. I’ll never have the wherewithal to own a J-boat, a downeaster, or a Gloucester fishing schooner, but I can own a trimaran, because it was designed for people like me to build, own and sail. That’s a pretty amazing concept in this world of specialized manufacturing, oven-baked carbon fiber race boats and the growth of the indentured class."

"Part memoir, part adventure story, part travelogue, totally compelling.”

— From reviews of Jim’s memoir, Among the Multihulls

Friends of Jim would like to give special thanks to Scott Brown. Without his help and support, none of this would be possible.

© 2024 Friends of Jim Brown

I used a Festool saw and guide to make the stems. The Festool guide and similar saw guides positively restrict the saw to move along a linear path only. These guides do not allow the saw to drift from the intended line unless something really awry happens. Before you lose interest on grounds that you don't have a Festool saw, the method described here will work for any circular saw guided by a straight edge that positively holds the saw to a straight line. I don't think that I would recommend this method with a mere straight edge that allows the saw to drift without positive control. The drift doesn't affect the workpiece since the drift away from the guide is into waste. However, saw drift while ripping or even crosscutting is not safe, particularly with thick wood blanks used to make stems.

Here is the method step by step.

Step 1: Make your blank(s) from suitable stock and layout your stem pattern(s) full size on the blanks.

Step 2. Drill two counterbores in the stem for mounting screws. See Fig. 4. I drilled counterbores that were 3/4 inch in diameter to fit the self-tapping Kreg screws I used for mounting the stem blank to the work table. Later these bores and the screw holes will be filled with epoxy.

Step 3. Grab some scraps and make the work table shown in Fig. 3. If you screw your head blocks to the table, position the screws well to the outside and make sure that your saw path will never hit them. In Fig. 3, my head block at the top of the table is way too short. I had to use a supplemental block to help support and clamp my saw guide to the table.

Step 4: Mount the blank to the table using self-tapping screws. I like Kreg screws for this. Position the blank so the cutting path runs up the table center and not through any screws on the outboard ends of the support blocks. The wide face of the stem faces up. You can position the stem blank anywhere you want so long as the saw blade path misses the screws. The main stem is 36 inches long, so this table is long to accommodate that stem as well as the shorter ama stem shown in the Figures.

Step 5: Clamp the saw guide to the table, aligned with the desired cut line. Both ends should be secured as we will need to make multiple passes. This Festool saw has a lot of power and can crosscut a 2 x 4 easily, but the saw has to work way too hard to rip this tapered bevel in one pass. So, I used four passes, cutting deeper by about 12 mm (about ½ inch) with each pass. Because the saw guide keeps the saw on line, each pass goes successively deeper on the same cut line as long as the saw guide is not moved between passes.

Step 6: Set the saw depth for the first pass, about 12 mm. Place the saw onto the guide in position and make the first pass. Then increase the depth of cut about 10 mm to 12 mm with each successive pass until the cut is complete.

Step 7: We want to make a stem with a cross section that is a trapezoid, not a parallelogram (I almost made some parallelograms). So, we need to remove the stem blank and remount it to make the proper cut. Remove the screws to free the blank. Turn the blank around so that the end that was at the head of the table is now at the bottom. The wide face of the stem is still facing up. If you do this right, the first bevel is now on the left and new bevel to be made is on the right.

Step 8: Secure the saw guide in position. Remember to clamp the guide at both ends so there is no movement of the guide during the multiple passes used to make the cut. Make sure you are cutting on the desired line and not the center line (I almost did this, too, on one stem). Double check to make sure the saw will not hit any screws at the foot or head of the table. If there is a screw in the way, you will need to move and remount the stem blank to avoid this.

Step 9: Again using four passes, cut the second beveled taper. Your stem is now done and can be removed from the table. The holes made in the stem for the counterbore and screws can be filled with epoxy to protect the stem from rot.

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Is anyone building a Searunner 31?

Discussion in ' Boatbuilding ' started by YMan , May 1, 2019 .

YMan New Member

I just found this site as I never considered building a sailboat before but am recently interested in the Searunners. Reading Jim Brown's books have given me confidence and inspiration. My plan has always been to retire into a traditional small cruising sailboat (Pacific Seacraft, Island Packet, Pearson Vanguard, etc). Downside is they are kind of slow; slower than my Cal 29 or especially the ultralights, and I would enjoy a lively boat for local sailing and fast passages. I started looking at multihulls, F28 and F31 in particular, but they aren't designed or suited to ocean crossings though they look like great fun. They did get me fired up about trimarans. Enter Searunner. It seems to me one of the smartest designed small cruisers around - as long as your idea of cruising doesn't require big electrical loads, diesel engines and modern conveniences. Some of those things interest me, but I consider worth sacrificing for fast, fun and safe cruising. Othe reasons I'm thinking of building one: 1. The design is simple and proven (designed for backyard builders). 2. The plans with full size patterns and a 400 pg construction manual are still available. 3. Materials are still available and overall cost to build and outfit seems to be about 3X-5X a used Searunner ($50-75K). 4. Most used Searunners were built in the 70s so the used market is thinning out and is 50 years old (like me). 5. A DIY build is the only way I would ever afford a new boat capable of world cruising (new hull, sails, rigging, wiring, etc) 6. John Marples who is a multihull designer and infinitely familiar with Searunners, and the Outrig.com folks are still around for support. 7. Building my own boat capable of crossing oceans in this day of outsourcing and buying from China is very appealing to me. Made in America. 8. Though it's an old design, many of us are still sailing plastic classics from the 60s and 70s and love them. The Searunner seems as comparable today for the cruising minded sailor and is faster. So, with what I believe are reasonable considerations and great benefits, I wonder why I haven't heard about others doing the same or seen new plywood & glass DIY multihulls in the marinas or oceans where I've traveled. And though I don't claim to be an expert on this subject, I'm wrapping up a 30 year combined navy and Coast Guard career, and I've seen a few marinas and spent a fair bit of time on the water. Am I missing something in my reasoning? Is there a hidden DIY boatbuilding scene in the US I don't know about? Or am I just an anachronism?  

fallguy Senior Member

I am building a Wood's Skoota 32 powercat. It was a two year plan, but hip failed and that added time to it. New Hip is better. I think I can finish in 3 years.  

rwatson Senior Member

In my humble opinion "The design is simple and proven (designed for backyard builders)." does not equal "it's an old design, .... Searunners were built in the 70s" The ease of building game, and designing game has moved way ahead in that time. This "homemade quality" and "old rugged design" philosophy is a bit overrated. I wouldn't build/buy a 1970 car either. A Searunner is no stronger than modern designs, but it is a lot heavier and lower performance with less room. Searunner Multihulls - Searunner 31 Trimaran http://www.searunner.com/index.php/searunner-trimarans/searunner-25/16-our-designs/searunner/34-searunner-31 Sure, you don't need speed in cruising, but if you can turn a 4 day passage into 3 days in fine weather, why wouldn't you ? I would be looking at places like M90 Trimaran | Build Your Own Trimaran https://trimarankit.com/m-90-stb-screecher  

RWatson: Thanks for the info. I'm glad to see there are new DIY plywood trimaran designs out there. I hope they are doing well at least in AUS. I looked over the M90 and would still prefer the SR31 for my interests. 1. The SR31 is about 30% heavier but is almost a meter longer. In the monohull world that is pretty equivalent for the length difference. Also, I think the liveable space is much larger and the SR31 almas are larger and provide some stowage, both of which account for added weight - the M90 has a very long, shallow stern cockpit more suited to racing and weekending in my view. 2. I much prefer the split cabin with captains berth and galley in the stern. The M90 v-berth doesn't suit me where the SR31 makes better use of the bow for sail stowage where sails can be handled thru the forward hatch. In military and commercial vessels no one but the lowliest sailor sleeps in the bow where pitching and pounding are the worst. Jim Brown puts the crew amidships where its comfortable and the captain in the stern where it's primo. 3. I would never want my galley next to my head. 4. The SR31 A-frames make incredibly strong support structures for the almas - like bridge trusses. I'm not sure about the M90. I'd be interested to know if anyone has done any significant cruising or ocean crossing in an M90. 5. I would trust the SR31 for good protection from heavy following seas. The M90 cockpit would certainly drain quickly but the crew would be at one with the sea (again more of a racing design).  

Ashantha Peiris New Member

Hello Mr Yman. We are qualified design and manufacturing team in FRP Boat Construction.we can design and manufacturing your boat as per your requirement . For More information please email to me. Email : [email protected]  

santacruz58 Senior Member

Hello Yman I don't know if you still follow this thread but I will comment anyway. I agree with your assessment of the sr31 for the most part. I have been looking at the sr31 as a cruising boat for my retirement. I don't plan on building one but would look for a more recent build that is in good shape. I have cruised in the past including ocean passages and I know how I would use the sr31. I like the eating and dining quarters separate from the sleeping and head area. In my research of this design the average speed on a passage is between 5 and 7 knots. A respectable speed, certainly faster than my last cruising boat. Standing head room is important to me as well as lots of usable storage space, thou you have to be very careful about how much weight is carried aboard. Kurt Hughes has recently posted on his blog that he has done an update on the sr31 on request of Wooden boat magazine. The design is definitely more modern with the nice hull shapes that he is known for. If I was going to build a new trimaran this size I would be knocking on his door to finish the design. All the best in your search.  

I sort of stumbled back into this thread while searching for SR31 info again. I think your speed should be a little better on a passage. Jim Brown quotes about 1.5X a comparable monohull into the wind and better on a reach. I've read several accounts of hitting approx. 15 knots and think between 7-9 kts on avg is doable. Since I started this thread I had a chance to look over a new build of a John Marples design DC-3 which is a trailerable 27' trimaran using his and Jim Brown's "constant camber" process, which allows a more open interior. I like the design a lot though it is quite a bit smaller than the SR31. It might work well as a single-handed cruising boat, but can't carry enough weight for more than 2 for any duration. The ability to save on slip fees and trailer all over the country is pretty appealing and my build space is a little small for the SR31, so I purchased the plans and am studying and preparing my home shop. In the meantime, I still have my Cal 29 to stay on the water and plan for the future. I do still keep an eye out for used Searunners - it could save me 3-5 years of building.  

HeyGuy New Member

YMan I have been rebuilding a 1976 SR31 A-frame , very strong solid boat, no dry rot, on custom built trailer. It has a 9,9 Yamaha out board, New folboat dingy w/2.5 motor, all riggings, sails- main, genoa and jib, custom mast step for raising and lowering aluminum mast and more. Electronics are out of date. Just needs hulls resurfaced and gel-coat. If you are still interested in getting into a SR31 let me know.  

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joe weaver New Member

I am interested in your 31 under restoration. Or any other searunner 31 for sale. Where is boat located? Email me please [email protected]  

anyone built from any of Glen L plans or Classic Wooden Boat Plans?

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Anyone has built a House boat here?

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Novi Lobster Boat plans needed.Can anyone help?

can anyone guess at what went wrong? Can peel fiberglass laminate off? 2-part epoxy

Anyone try to buy a windshield lately?

Anyone know what these tools are?!?!?!

Dry-rot elixir for plywood a recipe anyone ?

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Boat Profile

Seaclipper 16

A folding trimaran for the home builder

From Issue   January 2017

I ’ve built more than a few boats for myself in the past 38 years, and in all that time I have never been tempted to build a multihull. Why go to all the work of building two hulls, let alone three, when I’ve never found any of my single-hulled boats lacking in any significant way? I started getting answers to that question as soon as I stepped aboard a Seaclipper 16 designed by John Marples of Searunner Multihulls and one of nine designs in the Seaclipper series of trimarans. The hull is constructed of 7 sheets of 1/4″ six-ply marine plywood, five sheets of 3/8″ nine-ply, and lumber in commonly available sizes. Fiberglass-and-epoxy sheathing is optional. The instructions are geared for novice builders; full-sized templates for the bulkheads are provided in the plans. Stringers connecting the bulkheads define the shapes of the plywood panels for the hulls. The 15′ 11″ vaka (center hull) has a flat bottom that will take to landing on the beach without digging in or causing the kind of wear you’d get with a sharp V hull. The amas (outrigger hulls)  have bottom panels set at an angle, deeper outboard than inboard. This configuration adds a fin-like element for increased lateral resistance for sailing in shallow water with the daggerboard pulled up. The angled ama bottoms also present an edge to the water, keeping the amas from slapping the waves when they’re close to the water’s surface; it’s a quieter ride. The amas’ bottoms are positioned higher than the vaka’s bottom, so their edges are not subjected to wear when the boat is hauled up on a beach.

Each of the four swing-arm akas has three bolts: one securing the pivoting part of the aka to the ama, and two (one of those anchoring the shroud bridle) connecting the pivoting part of the aka to the fixed central section on the vaka. Removing the inboard bolt allows the swing arm to pivot, moving the ama aft and inward.

The akas (crossbeams) can  be made in three ways: as one piece bolted to the three hulls, hinged to fold the amas on top of the vaka, or as swing-wings, like LIMONADA shown here. With the swing-wing, the amas pivot aft and nest against the vaka, bringing the beam down from 11′ 3″ to 7′ 7″ for trailering and to fit in a standard marina slip. The swing wings can function whether the boat is afloat or on a trailer, so they are handy when launching or landing at a crowded boat ramp. The swing wings don’t require any hardware beyond nuts and bolts, and have an advantage over the hinged akas: there’s no need to lift an ama and set it down gently on the vaka. The Seaclipper 16 can be built as an open-cockpit cruiser, or as a daysailer with a tandem cockpit, with the helmsman sitting in the aft position, legs straddling a centerboard trunk and the crew sitting forward. The 7′-long open cockpit has side decks between the akas that offer more options for seating, moving around while under sail, and sleeping aboard while moored.

John Marples, designer of the Seaclipper 16 and builder of LIMONADA, goes for a sail on the Mystic River.

L IMONADA, as an open-cockpit version of the 16, has a daggerboard deployed through a slot in the cockpit sole. A softwood stick wedged in the slot keeps the board down; it has a loop of line at its top for quick removal and raising of the board. The cockpit sole is high enough above the waterline that any water coming into the cockpit drains right out. The rudder is mounted on a false transom, hinged at the top, that allows the rudder to kick up when meeting an unexpected shoal or to be retracted when coming ashore. The downhaul at the bottom of the false transom leads to the cockpit for easy operation. The rudder blade is balanced and has enough of the blade ahead of the pintles and gudgeons to lighten the load on the skipper when coming about. It also allows the arms of the rudder yoke to be short and unobtrusive. The lines from the yoke lead forward to pedals in the cockpit to  for hands-free steering. A tiller above the yoke allows steering while sitting on a side deck and is the means of raising the rudder when coming ashore.

A hinged false transom allows the rudder to be kicked up. The tiller pulls the rudder up and holds it. The line at the bottom of the false transom holds the rudder down while the boat is underway.

The Seaclipper 16 is designed to take a Hobie 14 sailing rig. The pivoting aluminum mast, roller-furling jib, and fully battened mainsail are readily available from a wide network of Hobie dealers and may be found used in online classifieds. The Hobie 14 has a beam of 7′ 8″, so the Seaclipper 16, with a beam of 11′3″ can take better advantage of the 146-sq-ft sail rig without flying a hull to the brink of capsizing. Dyneema shrouds, secured to bridles spanning the side decks, support the mast. The plans include specifications for an unstayed wooden mast. For auxiliary power, a short crossbeam aft of the port aka serves as a mount for a small outboard.

The side decks provide seating when two are aboard, and the steering is then done with the tiller, not the foot pedals.

I had a chance to sail LIMONADA, the Seaclipper 16 built by Marples for Mac MacDevitt, on Mystic River near Mystic Seaport. Stepping aboard, I got my first lesson in the values of a multihull. I didn’t have to lunge for the centerline as I do with my monohulls to keep them on an even keel. The trimaran has plenty of stability no matter where I put my weight and the amas (outer hulls) have enough volume of to support my 220 lbs. Without having my movement aboard the boat restricted by the nagging demands of a monohull, I could wander around the boat. The decks are all flat, so the footing is good everywhere. While I like the sweep of a curved sheer line, the Seaclipper’s flat decks simplify the construction of the boat and provide the geometry required for the swing-wing akas.

The deck surrounding the cockpit is large enough to set up a tent for sleeping at anchor. The windshield was added by the builder to block spray when sailing into a brisk breeze.

I liked being able to walk around the boat while it was under sail with Mac at the helm. I never get to see my own boats moving through the water, so stretching out on an ama to watch the vaka’s bow at work was a treat. The 7′-square deck around the cockpit offers a place to pitch a tent. Mac has a two-person tent with an oval hole in its floor to match the cockpit opening. He can sleep to one side of the cockpit, sit comfortably upright with his feet in the cockpit and have access to the gear stowed there. The amas and vaka offer plenty of room for cruising and camping gear; commercial plastic hatches offer access.

I took LIMONADA out by myself and enjoyed steering with my feet and having my hands free to manage the sheets. Nestled down in the cockpit on a padded seat with a backrest, I was very comfortable and relaxed. The sheets were right in front and could be cleated off, making sail-handling a breeze; there was no need to switch sides or do-si-do with a tiller when coming about. During my outing the weather was warm and the wind was light, perhaps 8 to 10 knots at best with a few gusts, but in a cold wind, being mostly below deck level would be a boon. Mac had made a removable windshield that wraps around the forward end of the cockpit for even greater protection from cold wind and spray.

With Marples and owner Mac MacDevitt aboard, LIMONADA flies the windward ama. The leeward ama still has plenty of freeboard.

The light wind was more than enough to get Mac’s Seaclipper going at a brisk pace and fly the weather ama. There was no spray, so I stayed dry, and even with the boat moving at a good clip I didn’t notice any water coming up through the daggerboard slot.

I was surprised by how well the Seaclipper could come about. With three hulls in the water, I thought there would be a lot of drag in the turns and that the boat would get bogged down, but the rudder blade and the centerboard have enough area to swing the bow around before the boat loses momentum. I never got caught in irons, but I backed the jib for a moment to hasten the bow’s falling off and the filling of the main.

LIMONADA owner Mac MacDevitt reports that his Seaclipper 16 is “super fun in a stiff breeze.” Here, sailing with a reefed main on Lake Champlain, he estimated his speed at about 13 knots. “It was exciting, but I felt safe and secure.”

Christopher Cunningham is the editor of Small Boats Monthly.

Seaclipper 16 Particulars

Length/15′ 11″

Beam/11′ 3″

Beam, amas retracted/7′ 7″

Draft, hull only/11″

Draft, board down/2′ 7″

Sail area/127 sq ft

Displacement, dry/400 lbs

Displacement, full load/800 lbs

Plans for the Seaclipper 16 are available from Searunner Multihulls for $180.

Is there a boat you’d like to know more about? Have you built one that you think other Small Boats Monthly readers would enjoy? Please email us!

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Comments (2)

Thanks for the multi-hull perspective. Lots of cool ideas.

I’ve been looking. This could be the one!

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Review of nine small, folding day-trimarans (2010)

by mike waters n.a.

As much as I like the basic concept of Jim's new boat, there are a couple of aspects that I need to mention. To put a light rig from a Hobie 16 on a boat that is FAR heavier and more stable than the boat for which it was originally designed, might prove too much for this mast, especially since the shrouds are more inboard than normal—so raising the mast compression. Normally, a Hobie would just 'go over' and so relieve the load—but not this beamy 800 lb twenty-footer! Also, the too-typical, puny 4-oz sail cloth of a regular Hobie 16 sail, is hardly man enough for this job. It's certainly a low cost start up solution and we've all admired Jim for his support to those with lesser means, but I think any builder should plan on something more substantial to be a better match for this cruiser. Finally, as the ama looks to be quite substantial in volume (guessing about 800 lbs buoyancy?), I have some concern for the strength of the single plank akas (cross beams) that act as swing arms for folding, should the builder decide to choose regular construction lumber. Sooner or later, someone will push this boat hard enough to bury an ama and that's a LOT of leverage on those arms, even if they are cleverly designed to act like huge flexible wooden leaf springs. But without seeing the details, I can only suggest that some good laminated material might be in order for these parts and perhaps Jim's plans already call for that or even some added carbon here as well. But I like the general concept and even though the boat will be no speedster, it's a design that can give a young couple on a small budget, a lot of weekend pleasure provided the conditions are within what the rig and swing arms can take.

• This particular Performance Index is simply a product of the principal things that affect multihull performance (LOA × BOA × Sail Area) all divided by the listed Weight. By taking the square root of this value, you then get a figure that very roughly reflects speed for comparison purposes. Yes, I agree there are a lot of factors NOT taken into account with this crude approximation, but the base figures used are easy to find and at least the general trend is indicated—and quite fairly so I believe.

TRIKALA 19 The Trikala 19 is from the board of imaginative designer Kurt Hughes. This boat was actually in production for a while in Spain but since then, a few have also been built by amateurs. A couple reportedly even cruised the Mediterranean in one! This is a boat design that always frustrated me—perhaps wrongly so.

For me as a designer, the looks of a boat are almost as important as its performance and the Trikala looks quite stunning from the bow, with its long fine entry and streamlined deck lines. But then, as it opens out to encompass a very wide cockpit aft, it always appeared to me that something distracted the designer or he just lost interest, as the view from the stern quarter is not so elegant. It's no doubt practical but it's a shame that its wonderful efficient appearance from the bow could not in some way be maintained at the stern. But with that very personal comment aside, this is an interesting boat with no doubt a good performance. It would be a particularly interesting boat to build for someone wanting to learn about composite construction with a larger boat in mind 'down the road', as the Trikala is lightly built of foam core under fibreglass skins and would therefore provide a good learning experience. The boat does not fold in a conventional way but like some other small designs by Kurt, uses a sliding system with tubular akas, the port ones, sliding into tubes with Teflon runners behind the starboard ones—so the two sides are not exactly symmetrical—a factor that some potential buyers find disturbing, though the difference is purely cosmetic. (The larger 7 m, L7 by Mike Leneman, also uses a similar sliding system – though in this case he uses fiberglass channels—see my REPORT on SMALL TRIMARANS for more on the L7, available through my website.)

W17 This design of mine was created during 2009 and completed in 2010.  It's hard to review your own boat designs without being accused of inevitable bias, so I will simply tell you about it and point out the features I've incorporated and why.  However, time has now shown [2020] it's as good as I had hoped and expected her to be.

This is a primarily a boat 'to just enjoy sailing in'. She's designed to be comfortable, way drier than average, fast and efficient and is just at home on a weekend camping cruise as on the circuit.   With several boats now [2020] having each sailed and cruised over 1000 miles and with open sea passages of up to 60 miles safely accomplished, she is certainly proving very capable in experienced hands, employing intelligent sail reduction when things get rough.   Her seemingly simple hull forms give a very high efficiency and she has proven quiet and dry through a chop and with her wing mast and unique ama shape, shows an unusual ability to climb to windward with minimal leeway.   [Following an independent test and review by Wooden Boat Mag., I was asked to explain why the W17 performed so well with such simple shapes and my reply to this was published in the prestigious Professional Boatbuilding magazine #169 .. and is available to read on this website under 'Published Articles'].    

Sailing this boat is indeed a magical experience and dozens of boats are now (2020 update) being built in over 30 countries.   She's a little more time-consuming to build than others her size, but numerous owners have since dubbed her, 'The Miata of the Seas' .      For them, a few more hours is well worth the effect and this boat will take you to a whole new level above any production boat of this size out there .... and also cost you less.

Comparison Chart  (created in 2010)

About Dick Newick

email for Plans

Dick Newick

"People sail for fun and no one has yet convinced me that it's more fun to go slow than it is to go fast."

All Designs

Moxie in the Azores

"For this, his third attempt at the OSTAR, Weld had Dick Newick design him the trimaran Moxie. In design, construction and in every piece of equipment Moxie was built to win. Phil Weld knew what it took to race across the Atlantic - the boat and the man were made for each other."

"By breaking the barriers of both performance and acceptance, Dick Newick can be called the Chuck Yeager of multihulls" -- Jim Brown, Wooden Boat magazine, May 2008