Is anyone building a Searunner 31?

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

  1. YMan
    Joined: May 2019
    Posts: 3
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    Location: Long Beach, CA

    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 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?
  2. fallguy
    Joined: Dec 2016
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    Location: usa

    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.
  3. rwatson
    Joined: Aug 2007
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    Location: Tasmania,Australia

    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

    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
    Dejay likes this.
  4. YMan
    Joined: May 2019
    Posts: 3
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    Location: Long Beach, CA

    YMan New Member

    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).
  5. Ashantha Peiris
    Joined: May 2019
    Posts: 2
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    Location: Sri Lanka

    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 :
  6. santacruz58
    Joined: Oct 2014
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    Location: lower hutt,NZ

    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.
  7. YMan
    Joined: May 2019
    Posts: 3
    Likes: 0, Points: 1
    Location: Long Beach, CA

    YMan New Member

    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.
  8. HeyGuy
    Joined: May 2021
    Posts: 1
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    Location: Idaho

    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.

  9. joe weaver
    Joined: May 2021
    Posts: 1
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    Location: New mex

    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
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