What hull do you think works best? (need a hull that runs shallow, holds 8500#, and ...)

Discussion in 'Stability' started by Jim Allen, Nov 23, 2017.

  1. Jim Allen
    Joined: Nov 2017
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    Jim Allen Junior Member

    Hi, I am new to this site and I have a question that I hope has an answer. I am a commercial fisherman and I have used a 24 Carolina skiff for the last 15 years. The pros are it holds a decent amount of weight. That's it the rest of it is bad. Heavy, flat bottom, hard on the kidneys, wet in any seas. My question is I need a hull that runs shallow, holds the same weight as my Carolina which is about 8500# and doesn't beat me senseless. Now I have bought a panga from China and from what I can tell it mite be the answer except for one thing. It's super narrow. At 77 inches for the 25 foot that's much less than the 89 the Carolina has. Volume wise the panga has much more however, I don't see it running as shallow with a load. Does anyone have a hull design that would fit my needs..run shallow, hold weight, and preferably a v hull to cut down on spray. Sides can't be too high as nets are too heavy to lift over 35 inches. Thank you
     
  2. HJS
    Joined: Nov 2008
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    HJS Member

    On behalf of Stephen Ditmore, I have sketched on a variant of Lobster boat. The intention is to create a boat for work and leisure that has the traditional boats function, a shallow depth and high load capacity but with much better features. This hull can be adapted to your needs.

    Welcome aboard

    JS
    Lobster a.jpg Lobster f.jpg Lobster p.jpg
     
    Last edited: Nov 26, 2017
  3. Mr Efficiency
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    Mr Efficiency Senior Member

    A 24' planing boat carrying 4 tons sounds way out of the ballpark to me. And elsewhere you mention a foot of draft, for that to happen the only possibility would be a flat bottomed, rectangular plan vessel that would still scrape the bottom at rest. I assume you want something around 25 feet with a maximum beam of 8 feet, still reckon that can't be done with any sort of speed, with all that weight.
     
  4. goodwilltoall
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    goodwilltoall Senior Member

    Abbondanza by phil bolger Abbondanza.gif
     
  5. TANSL
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    TANSL Senior Member

  6. HJS
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    HJS Member

    Yes, my proposal is a shallow depth boat. The important thing in this context is that the large propeller and the rudder are well protected by the box keel.

    JS
     
  7. TANSL
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    TANSL Senior Member

    I think it would be more appropriate to use a displacement hull, with polyhedral shapes in the stern (that is, not rounded "U" shapes) with a tunnel to house the shaft and the propeller. Those shapes would allow it to carry the max of payload with the less of draft.
     
  8. Mr Efficiency
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    Mr Efficiency Senior Member

    Not enough info supplied about what the boat actually must do, but I am not buying that a 24 foot boat can be loaded up with 8500 lbs and plane.
     
  9. Raffaele Frontera
    Joined: Feb 2018
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    Raffaele Frontera Naval Architect

    Hello @Jim Allen,
    good evening.

    I would like to ask you, why do you need a v hull? Which is the speed of your boat that make you think that you need a v hull?

    Thank you and Best Regards

    RF
     
  10. Yellowjacket
    Joined: May 2009
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    Yellowjacket Senior Member

    I'm assuming that you want to get to the fishing area quickly, load up and then get home reasonably fast.

    If so then the answer is (with apologies to Roy Schieder)..... "You're gonna need a bigger boat"....

    Or in the football analogy think seriously about "going long"...

    Your draft is a function of bottom area. To minimize draft, you want a low bottom loading (less pounds per square foot of bottom area)...

    Unfortunately, when you go to a low bottom loading you're going to pound. The more surface are you expose to the water, the faster and greater the load you put on the hull so that creates the pounding...

    The way you can mitigate that is to go narrower and longer, but to have the same draft you're going to have essentially the same bottom area, but with less beam you'll have a finer entry and with longer length you won't tend to pound as much.

    A deep V hull will draw more water, but it will ride better. You could go with a good bit longer hull and keep the beam low and add some V and probably get a much better ride than what you have now, but don't expect miracles.
     
  11. Raffaele Frontera
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    Raffaele Frontera Naval Architect

    I liked your explanation @Yellowjacket :)


    Yes, it is exactly my point, that's why I am curious about why he need the V hull.

    Regards,

    RF
     
  12. TANSL
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    TANSL Senior Member

    Although Jim Allen seems to be missing, maybe he will not mind getting answers, I will do the following question: would not it be possible to increase the height of the bulwark (and fore deck if any) in the bow area, in his 24' Carolina skiff?
     
  13. PAR
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    PAR Yacht Designer/Builder

    The box keel approuch does work, offering the fine and sea keeping entry of a deeper V hull while supplying shoal draft and load bearing aft, so she can offer some capacity. I have a 37' box keel boat (John Atkins) and it's efficient (pure displacement) and shoal (27" on a 34' LWL at 18,000 pounds). Full plane mode versions of these aren't as common, though do exist and you get decreasing amounts of ride quality and efficiency as speeds rise over a certain point. They excel at semi displacement speeds.
     
  14. Yellowjacket
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    Yellowjacket Senior Member


  15. Raffaele Frontera
    Joined: Feb 2018
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    Raffaele Frontera Naval Architect

    I agree, the box keel for shallowe water it is the best solution. I don't see the possibility for the V hull.
     
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