Please Review Hull Form

Discussion in 'Boat Design' started by daydreamer, Mar 15, 2020.

  1. daydreamer
    Joined: Mar 2020
    Posts: 1
    Likes: 0, Points: 1
    Location: Puget Sound, WA

    daydreamer New Member

    Hello Everyone,

    I am hoping that the forum can provide commentary on some hull lines that I am working through.

    A little bit about the concept: An economical powerboat to operate on a semi-planing hull in partially protected waters with specs as follows:

    LOA: 32.5'
    BOA: 8'-6"
    Draft: Approx. 1'
    Displacement: 7,200 lbs (typically loaded)
    Desired Cruising Speed: 12-15 knots
    Desired Max Speed: 20 knots
    Hull Construction: Aluminum

    This warped hull form is partially based on the NTUA series (in paticular the double-chine aft).

    Please provide some general commentary/an informal peer review. Any feedback is appreciated!


    Attached Files:

  2. gonzo
    Joined: Aug 2002
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    Location: Milwaukee, WI

    gonzo Senior Member

    It's an ancient design. You can get plans that are proven to work well for very cheap from old designers; probably their estates. The cost of plans is one of the least when building a boat. That weird facet on the aft chine seems counterproductive. At semi-planing speeds you want a clean water exit. That looks more appropriate for low speeds. The deep forefoot will likely trip in following seas and make the boat broach. How are you getting a displacement before having weights from all the structure, machinery, interior, etc. ? Also, with a draft of 1' you would need a tunnel to accommodate the propeller and rudder, and it would only have space for a tiny one.
    Last edited: Mar 16, 2020
    bajansailor likes this.
  3. DCockey
    Joined: Oct 2009
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    Location: Midcoast Maine

    DCockey Senior Member

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  4. JSL
    Joined: Nov 2012
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    Location: Delta BC

    JSL Senior Member

    all good observations & advice.
    You have what some call a 'double wedge' hull form. (see sketch)
    Deep forefoot/shallow stern + fine bow/broad stern = broaching hull form.
    I have had the (dis) pleasure of operating a few of these creatures and they are trouble. And, your 'hollow' flare bottom will only contribute to the problem.

    Attached Files:

    Last edited: Mar 20, 2020
    bajansailor likes this.
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