DIY Kayak Design

Berny Marsden’s Stitch and Glue W Kayak – United Kingdom

This is the latest DIY W kayak project –

It’s the first DIY design allowing to take the boat apart.

Read Berny’s account on the comments section:

NEW: View Berny’s first test movie of his motorized W kayk ‘Banana Split’ –

More info here >

John Forney’s Wooden W Kayak – Texas

John is an prolific small-boat designer and builder from Texas, who’s built fifteen boats in recent years, including designs in wood, composites and skin-on-frame.
John says: -“My interest in boat building had waned somewhat, primarily because I couldn’t crack the nut of fishing comfortably from a small paddle craft. The W concept has completely reinvigorated my interest in boat building.”
John first W boat is 12 feet long and 30 inches wide, and it weighs 74 lbs. It can take two large size fishermen with all their fishing and camping gear.
-“Standing up in this boat is as natural as breathing.  One just doesn’t get the sense that anything will go wrong.” he says.
John’s next project is a ten footer skin-on-frame W kayak.

Email John Forney


John standing in the wooden twin hull fishing kayak he created

“I’m on the Brazos River with my wife this day. I painted the boat Navy Blue Marine Polyurethane paint on the outside, with white Marine paint on the inside.”

Wooden twin hull fishing kayak / unfinished
Wooden twin hull fishing kayak / unfinished

Wooden twin hull fishing kayak / unfinished

16 ft Long Fiberglass W Kayak

This is a 16 ft long W kayak project realized in Europe:

16 ft long W kayak - Europe

16 ft long W kayak project – Europe

The design of this fine looking W kayak was based on a concept published on this website back in 2006:


Concept W Sea Kayak – 2006


More technical info on speed, stability, propulsion ergonomics and other design issues related to fishing kayaks >


  1. fishingkayaksdesign (Post author)


    John is a bit slow to respond, so I’ll provide you with some information –

    1. What thickness of plywood did you use for the hull skin. Would 6mm (1/4 inch) ply be thick enough?
    2. Are the bulkheads and seat plank made of thicker plywood (3/8 or 1/2 inch)?
    -No need for that. Howver, your biggest challenge is to prevent the hulls from splaying. You can achieve that by introducing gussets (structural reinforcement ribs) under the top of the saddle, as it was done in the commercial W500 kayak.
    3. Are the two hulls parallel or are they wider at the bow than at the stern?
    -John’s hulls are symmetrical bow and stern, as is the commercial W500 model. Note: for more efficiency, each hull should be asymmetrical, with the side that’s facing the other hull straight and flat, and the side facing outward curved. This optimizes the inflow between the hulls, and minimizes turbulence there.
    4. Did you use stitch and glue for the construction?
    -That’s for John to answer
    5. Did you fill the bow and stern compartments with expending foam for emergency buoyancy?
    -Not necessarily a good idea, since this internal space has value for dry storage. You’d better attach detachable polyethylene foam flotation (pool noodles) below the saddle, and on the kayak’s sides.

  2. fishing kayaks design (Post author)


    2 divers + 2 sets of diving gear is about 500 lbs, isn’t it?
    Not sure your 12 ft design would be optimal for this load, especially in the ocean.
    You may want to make your W slightly bigger.

  3. John Forney

    I’m glad to see you pursuing a home-built W kayak design. Yoav has a great design available commercially, but a homebuilder can pursue interesting inroads to the design on his own.
    I used 1/4″ plywood, sheathed in 6 oz. fiberglass for the hull. I used some strips of pine lumber for reinforcement. Two strips, 1 1/2″ wide by 3/4″ thick, went across the boat above the bulkheads at the ends of the saddles. I also put two gunwales outside the plywood, running the lengths of the boat. Underneath, I fastened two supports that looked a little like a crescent, to stabilize the two hulls. I’ll upload pics to Yoav for further description of this.
    The hulls were parallel to each other, but they were asymmetrical when viewed from the ends of the boat. The outside of each hull was more curved than the inside. If you’ve ever seen a proa, you can see the parallel. After conversation with Yoav, he persuaded me to make the insides more parallel and vertical. That was a good choice.
    I used the stitch and glue method. I’ve built several CLC kayaks and pirogues, so this method was comfortable for me.
    I didn’t use any expanding foam, and didn’t see the need, with enclosed bulkheads.
    Here’s what I would do differently:
    1) I’d focus on weight reduction. 74 lbs. is too heavy for a 12 foot boat, especially a stitch and glue boat! Okume plywood, cedar lumber, less fiberglass, lighter (4 oz.) fiberglass, no bulkheads, etc.
    2) I’d make the saddle 6 feet, not 8. We tried to make a 2-person boat. It was plenty beamy, but too short. Have you ever seen an 8-foot two person canoe? You get the picture.
    3) I’d taper the hulls more. The boat created quite a wake at hull speeed. This slowed down the top speed for a 4-mile trip I did on flat water. I did outfish everyone else, though! 🙂
    4) You don’t need four bulkheads. I’d make one or two at the most. Dry bags and an open space is better and lighter, I think.
    5) I’d really like to explore this design in skin-on-frame. Think of something like a long, stable coracle that you could carry easily.
    The design is really unique in the fishing world. I am very interested in seeing how people compensate for increased wetted surface area and weight to make it faster. Good luck, and post pics! John Forney

  4. fishing kayaks design (Post author)

    Hi John,
    Increased wetted area is largely compensated by the dramatic reduction in beam width, I.E. Residual Resistance (Rr), which becomes the dominant factor as speed goes up.
    See kayak speed >>
    Catamarans are heavier than comparable mono hulls, but this factor is overrated in such tiny boats, where the passengers’ weight is several times the boat’s weight.
    For example: A kayak weighing 70 lbs and carrying a 200 lbs passenger (total 270 lbs) weighs just 2.7% more than a kayak weighing 63 lbs carrying the same passenger (total 260 lbs).

  5. fishing kayaks design (Post author)

    The W500 saddle is 12.5″ wide at its bottom, and it tapers in its upper part, for more comfort in sitting / standing. The very top of the W500 saddle is less than 10″ wide, and the edges are rounded, which is easy to achieve in plastic, and probably harder in wood 🙂

  6. fishing kayaks design (Post author)

    Here are more pictures that John sent me for uploading:

    view of wooden catamaran fishing kayak

    close up view of wooden catamaran fishing kayak

    Under view of wooden catamaran fishing kayak

    Says John: -“…I can’t stand the traditional recreational kayak, and I don’t think other folks like them much, either, after they spend some time trying to fish out of one.
    Attached are some pictures from the wooden W boat project. I’m not going to work on another one in the forseeable future; I’m working on developing my skin on frame skills.
    I’ll be checking back periodically to see how things are going…
    John Forney”

  7. fishingkayakdesign (Post author)

    The 16 ft long W kayak seen here would have solved some of the issues mentioned in this kayak review of the 11ft long W500:

  8. fishingkayakdesign (Post author)

    Thanks Berny,
    Looks great!
    I like the idea of being able to take it apart. It’s useful for storage and transportation.
    With two passengers plus gear on board, these aluminum tubes you’re using to attach the 3 pieces together might bend.

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