what is faster a flat boat hull or a vee pad hull

Discussion in 'Boat Design' started by riveramunizaga, May 3, 2005.

  1. riveramunizaga
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    riveramunizaga Junior Member

    what is faster, a flat boat or a paddles vee hull, whay??


    thanks
     
  2. mackid068
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    mackid068 Semi-Newbie Posts Often

    Um. Hm....it really depends. For overall, I'd always go with a V, at least under power. Flat? I don't know, but flat boats do plane.
     
  3. cyclops
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    cyclops Senior Member

    Flat will plane with less horsepower at the lowest speed. The faster one has the bigger engine. Cyclops rules of speed: flat stones bounce several times across the water surface farther, than round or angular stones.
     
  4. riveramunizaga
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    riveramunizaga Junior Member

    cyclops you are ok........... but remember that the vee hull with pad, the pad is flat and what happen abut it.
     
  5. yokebutt
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    yokebutt Boatbuilder

    River,
    A flat bottom will go faster, but having your kidneys fall out of your lower orifice might detract slightly from the experience.

    Yokebutt.
     
  6. cyclops
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    cyclops Senior Member

    The planing pad on all newer boats will go fast with the deep V and keep you safe. Go very fast on a flat. Orrrr. Arrive a little later and help others find " Flaties" body. Your choice.
     
  7. marshmat
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    marshmat Senior Member

    The flatter the hull bottom is, the more efficient it is at generating lift.
    As you go to greater and greater deadrise (sharper V), the hull will require more power to maintain the same speed as a flatter bottom of equivalent dimensions and weight (because lift is perpendicular to the running surface, the lift drops off with the cosine of the deadrise angle as you increase the deadrise).
    As the water gets rougher, a flatbottom will begin to pound, the whole bottom hitting the surface of a wave at once. This wastes a LOT of energy and slows the boat down. A vee will cut the waves better and maintain a steadier speed.
    The sharper the V, the more power you need for a given boat speed; however, each hull must compromise between efficiency and wave-handling ability.
    With a pad, you are adding a flat area near the transom. This flat area generates lift more efficiently than the vee part of the hull, and it is located far enough back that it does not have to slam into waves. Non-constant deadrise (modified-V) and padded V hulls are different compromises between flatbottom efficiency and V-hull wave handling.
     
  8. bsmit24
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    bsmit24 Junior Member

    I have read and heard before that the vee gets more effecient as the speed increases. Is this true or is simpily the bouncing issue that you mentioned?
     
  9. riveramunizaga
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    riveramunizaga Junior Member

    for a 16 feet boat, 22ยบ deep-v, 77" of beam, what is the perfect pad that i will need to build, for the best performance.?
     
  10. mackid068
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    mackid068 Semi-Newbie Posts Often

    Go for the V hull for comfort.
     
  11. mackid068
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    mackid068 Semi-Newbie Posts Often

    V hulls are supposedly better for turning (or at least, it seems like it...)
     
  12. cyclops
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    cyclops Senior Member

    Are you intending to build a boat from what is said here?
     
  13. marshmat
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    marshmat Senior Member

    bsmit- the reason the deep-V is good at high speed is that it cuts the waves rather than pounding into them. It is never an efficient hullform, not in terms of the lift it generates at least. The reason it is so common is because it gives a nice ride in chop.

    mackid- yes, a V is better in turns than a flattie. Turning causes the boat to bank inwards; the inboard bottom then provides the lift while the lift from the outboard bottom helps push the boat around. THe keel helps it track smoothly. A flattie simply skids all over the place unless it has keel fins to provide something to brace against while turning.
     
  14. mackid068
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    mackid068 Semi-Newbie Posts Often

    Soooooooo...the V is the best for performance, unless you want a WIG or a hydrofoil.
     

  15. marshmat
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    marshmat Senior Member

    Depends how you define performance, and in what conditions.
     
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