Planing hull strake design questions

Discussion in 'Boat Design' started by waverider, Oct 13, 2012.

  1. waverider
    Joined: Oct 2012
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    Location: Hawaii

    waverider New Member

    I have an old 15' Chrysler hydro-vee that I've been rebuilding.I noticed that the lines of the strakes seem to "camber" or bow down at the last foot and a half or so right before the stern,they drop about a 1/4 inch.My question is; Are some boats designed this way,maybe to get the boat on plane faster,like a trim tab or am I looking at some kind of warp problem from the rotten transom that I already replaced,also the camber only seems to be on the outside edge of the strakes,the flat planes of the hull in between the strakes have no curve and are all straight.
  2. messabout
    Joined: Jan 2006
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    Location: Lakeland Fl USA

    messabout Senior Member

    Seems that no one else is inclined to comment about this glitch. I will stick my oar in the water here on account of your having been ignored.......

    If the "hook" is only near the chine it probably will not matter much. Actually it depends on the area of the hooked part. If the quarter inch downward slope is part of a long triangular section then I'd not be much concerned. If it is a short triangle I might think about it more seriously. If your desire is to go very fast then this might matter a bit. If you are happy with 25 knots or so then forget that you even noticed it. On the other hand there are some super fast boats that deliberately use a feature of this sort.

    Whether the hook was a design element is hard to say. I wouldn't think so, but who knows? Finish the boat and enjoy it.
  3. PAR
    Joined: Nov 2003
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    PAR Yacht Designer/Builder

    Welcome to the forum Waverider, sometimes we're slow, but hopefully only in reply time.

    Most often with 'glass trailered boats, the trailer bunks or supports do this to the boat, if improperly setup. Without pictures it's tough to tell. A hook wouldn't be typical of most relatively modern powerboats (built after the early 60's), so it's probably a trailer induced hook. Post a picture and we'll have a look.

  4. waverider
    Joined: Oct 2012
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    Location: Hawaii

    waverider New Member

    Thank for replying ,I did figure out how to fix it,although I was afraid it was too late,because after rebuilding the transom,my next step was building a drain well ,in which I glassed two small 30" stringers to the transom connecting them with a small 30" bulkhead,its part of the original design where the water from the deck drains into the little square well.So since the strakes that are hooked the worst are directly under these little stringers,what I did was just simply cut them away from the transom to get some movement,after I was able to take a 2 X 4 and attach it across to the sides of the hull above the little bulkhead ,then I placed a small piece of plywood on top of the frame and placed a car jack right on the corner of the stringer and bulkhead and presto!,no more hook. There is still a little slight hook in all the strakes including the chines,but we are talking only about 4 inches long from the stern,,very minor,its gonna be a fishing boat,not a speed boat.When I first tore out the floor I discovered ,aside from the rotted drain well frame,it was designed with no stringers,just filled with water logged polyurethane foam,so with a rotted deck ,transom,etc, and a 65 horse outboard on it,this boat was under a lot of stress and I believe thats how it got hooked along with the junk trailer it came with.Also I'm placing real stringers in this boat and I'm gonna extend the stringer above the strakes that were hooked,to keep them in shape. Thank you again for your expertise.
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