prop pocket or delta section?

Discussion in 'Boat Design' started by kapnD, Sep 20, 2003.

  1. kapnD
    Joined: Jan 2003
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    Location: hawaii, usa

    kapnD Senior Member

    Which would be more effective means of achieving vertical prop clearance? Hull is 29'x9' fg steep entry, hard chine, warped bottom to 12 degrees at transom. Am leaning toward the delta section, maybe 8'Lx2'W, thinking that the break in the keel line might bring the bow up at planing speeds, not necessarily a bad thing on a warped hull! Would this also give a cleaner wake at displacement speeds? Any thoughts, comments?
     
  2. gonzo
    Joined: Aug 2002
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    gonzo Senior Member

    Could you describe the Delta section?
     
  3. Tad
    Joined: Mar 2002
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    Tad Boat Designer

    I believe you are refering to cutting off the tip of the vee bottom?

    This may work. You are reducing volume aft, the boat will float a little lower aft. The low deadrise (perhaps 0?) section will act like a pad and increase lift aft, therefore the bow will come down at speed. This could be a bad thing if it changes trim too much.

    good luck, Tad
     

  4. kapnD
    Joined: Jan 2003
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    kapnD Senior Member

    Gonzo, Tad describes the delta above. I havent the foggiest clue how to design the section, but have seen it done on many deep vee hulls with quite some success. Believe these were all seat of the pants designs, no number crunching involved. Guess the danger lies in making it too large, causing the boat to ride completely up on top of it and pounding like a flat bottom. My boat is not overpowered, so I'm thinking that 8'long tapering from nothing to 2' wide at the stern should give me the prop clearance I need and possibly some planing assistance. Saw an ad for a large sportfisher where the delta section held a trimmable surface!
     
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