Hull shape: what’s the consensus on extreme piercing/displacement/planing combo hulls for sailboats?

Discussion in 'Boat Design' started by Kingston, Sep 13, 2018.

  1. Kingston
    Joined: Sep 2018
    Posts: 9
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    Location: USA

    Kingston Junior Member

    I'm hoping to keep things easier by working on a small sailing dinghy. Perhaps plywood would be a good choice for cheap hull experimentation?
  2. upchurchmr
    Joined: Feb 2011
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    Location: Ft. Worth, Tx, USA

    upchurchmr Senior Member

    Plywood is great.
    Do you know anything about working it?

    Some Naval Architect will have a better suggestion, but why don't you buy one of the books by C. A. Marchaj.

    Then order a set of plywood boat plans for a 12 - 15 ft boat, and build it.

    Try to understand the boat you built in terms of the book.

    Then think about reinventing the world.

    Commenting about your drawing.
    The wide/ fat displacement section is way too short. The aft slope is too steep.
    The flat aft section will do nothing since sailboats heel, and the only thing left in the water will be a triangular section way off to the leeward - so there will be no planing.
    You need to figure out how to determine what the bouyancy of your hull is. You have way too much in the front and too little in the back.
    Just imagine what would happen if you actually sat on the boat in a normal position - the stern would be underwater.

    TANSTAFL - there is no such thing as a free lunch.
    Even with plywood you are going to spend plenty of money. If you use the cheapest you can count on it not lasting very long.

    What 16' boat were you sailing on?
  3. BlueBell
    Joined: May 2017
    Posts: 788
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    Location: Victoria BC Canada

    BlueBell Ahhhhh...

    Plywood is excellent.
    Stitch-and-glue is easy, strong and light.
    Google it.

  4. Dolfiman
    Joined: Aug 2017
    Posts: 979
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    Location: NICE (France)

    Dolfiman Senior Member

    In case of, you can also be inspired by this dinghy design, Kitoo simple , a DIY but with a sophisticated plywood structure to make a light rigid hull (all elements being carefully computed and cut), with a modern hull shape as you would like, and finally easy and fun to sail, stable enough for all level of skills : Kitoo Simple : le dériveur en kit plein de sensations
    Doug Lord likes this.
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