Help designing a 12' PowerCat deck boat (3d model inside)

Discussion in 'Boat Design' started by Huntersirg, May 31, 2011.

  1. Huntersirg
    Joined: May 2011
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    Location: Clearwater FL

    Huntersirg New Member

    This will be my very first boat building project. It will be used mainly for teaching kiteboarding and short runs out to some barrier islands. It will need to plane and at least do 15mph (w/ a 10-20hp outboard). It does get very shallow on low tide in the flats and I'd like to keep it light and design it to have a shallow draft. I need the front seat to flip down to the water to make it easy to get in and out (also used to sit on while instructing). I will be taking it through some chop so I'd like it to cut through small waves (pointed bows).
    Looking to build this cheaply with 1/4" lauan ply for sheeting the hulls, taped seams and a layer of fiberglass and epoxy on the outside.
    I've searched all over the net for free plans that I could modify or just small boat plans I could build two of and connect them. Problem is none of them seem like they would plane well or have the shallow draft I'm looking for.
    Any help on this venture would be greatly appreciated!!

    Thanks in advance.



  2. grandpaclint
    Joined: May 2011
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    Location: golden valley, az.

    grandpaclint Junior Member

    that seems like a nice idea, but I sure wouldnt want to take in any rough water
    I have a 17 ft. power cat original,,,,it will take almost anything
    good luck
  3. Huntersirg
    Joined: May 2011
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    Location: Clearwater FL

    Huntersirg New Member

    Thanks I'm hoping this will be a fun little boat to run around and teach off of. The most it will see is 2-3 foot chop mostly run in shallow protected waters. I found the Bateau cheap canoe plans seem like they will work well if i modify them to go straight from the center point back with only rocker in the front, then close off on the top.

    The triangle in the center is to help with the cavitation issues I've read about with single center mounted outboard cats.

    What type of hull will this be and what sort of top speed could I see if I kept it light with a 10-15hp outboard?

    Another thing I can't figure out is how they would be connected with enough strength to not be ripped apart???

    I was thinking a few 2x4 frames inside the hulls screwed to 2x4 on the outside with 2x6s front and back connecting and maybe one in the middle Will this be enough?

    Got a better idea? Please let me know. Plenty of views just no advice on if I'm going to right direction with this??? Thanks.


  4. keysdisease
    Joined: Mar 2006
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    Location: South Florida USA

    keysdisease Senior Member

    Your plans to use 1/4' plywood for the hulls is fine, I would leave the glass off and just epoxy coat the hulls. One layer of glass really doesn't bring much to the party.

    A simple box beam for the crossarms would be simple, strong and light. The after one a little heavier because of the motor, maybe two 2 x 4's 4" apart and joined top and bottom with 1/2" ply. A simple 2 x 4 "bulkhead" every foot or so. It would mount with the 2 x 4's vertical.

    The front could be 1 x 4. You might also want a 2 x 4 from the center of the aft beam going forward at 45 degrees and tieing into a hull frame there to help with engine thrust.

    The deck is probably going to have to be 1/2" for all the abuse it will take. A few 2 x 4's across from hull to hull to help stiffen and the 1/4' skin across the bottom to keep waves from slapping. This will also give you a cavity you can cut a few hatches into for some storage.

    Forget the V thing, but be sure you make your motorwell so you can tilt the engine all the way up. 6 gal plastic fuel tank under the seat.

    I see you guys when I cross the Skyway about once every 6 weeks on biz trips. Looks like you're having a blast out there.


  5. philSweet
    Joined: May 2008
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    Location: Beaufort, SC and H'ville, NC

    philSweet Senior Member

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