Beach launch compact fishing design

Discussion in 'Boat Design' started by IronPrice, Jul 17, 2017.

  1. Mr Efficiency
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    Mr Efficiency Senior Member

  2. Mr Efficiency
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    Mr Efficiency Senior Member

    Transom deadrise.....10 degrees approx
    Chine width @ transom.....4'6'' minimum
    warped plane bottom, 20" transom height (open)
    20hp would be enough if built light
    full forward sections to limit bow dip, and improve stability. In a small boat on the big sea, you want the bulky bow !
    Length 13 feet minimum
    Straight hull sections, no developable surfaces needed with PVC foam
    forefoot not too deep, just enough to offer a reasonable cut-water, not enough to encourage broaching.
    I have no idea if any similar boat plans are available. :(
     
  3. IronPrice
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    IronPrice Senior Member

    What do you think about a 16 degree dead-rise with about a 1 metre internal beam with additional width from side sponsons that also function as reverse chines?
     
  4. Mr Efficiency
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    Mr Efficiency Senior Member

    You can get "boat collars" that act as side sponsons with a reverse chine effect........ 4476639_orig.jpg
     
  5. Mr Efficiency
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    Mr Efficiency Senior Member

    I really can't see how one man can easily launch a small boat off a steep beach, where there isn't a gutter, just a nasty shore dump.....
     
  6. IronPrice
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    IronPrice Senior Member

    Are you familiar with stabi craft?

    I imagine a stabi craft about 3.6M long with an internal beam of 0.8 metres.

    Tonnes of buoyancy, reverse chines to assist stability at rest/anchor, narrow cross section for reduced mass/wetted area/frontal drag, wide gunwales to sit on.
     
  7. Mr Efficiency
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    Mr Efficiency Senior Member

    I have seen stabi-craft, not a fan of that type of thing, really. And your weight specs won't be met, surely ? The 14' stabicraft is 230kg dry weight. Why do you want the narrow internal space ? Certainly such a boat can survive better being swamped, it does seem to be an analogue of an inflatable, in that respect. I'd rather keep the water out of the boat, and in a beach launch situation that is always on the cards, with low freeboard at the bow, and/or lack of fullness forward. I really think 3.6 m is too small for any open water situation, and 4m should be your bottom limit, and preferably 4.3m
     
  8. Mr Efficiency
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    Mr Efficiency Senior Member

    An open boat with a high peak at the bow, is a bit of a nuisance in normal operations, with tiller steer ( a must in your situation) it makes forward visibility a problem, and also puts the boat more under the influence of cross-winds, but it is useful to keep water from entering the boat, running a break.
     
  9. IronPrice
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    IronPrice Senior Member

    Timing - if you wait there is always a big enough gap. The steeper the beach, the easier it is. The smaller the boat the easier it is.
     
  10. Mr Efficiency
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    Mr Efficiency Senior Member

    A small tin boat with the boat collars might do the job. The collars weigh not much at all.

    broach-1-1-1-a-chop.jpg
     
  11. Mr Efficiency
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    Mr Efficiency Senior Member

    ......those collars would also offer a nice buffer to being belted on the legs by the boat.
     
  12. Mr Efficiency
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    Mr Efficiency Senior Member

    I am not familiar with that situation, really, I guess the locals have nailed down the right technique.....
     
  13. IronPrice
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    IronPrice Senior Member

    I want a small and light boat, narrow is just a way of achieving that.

    I'm prepared to tolerate small and narrow because I currently fish out of a kayak (0.83m external beam), launching from the same launch spots.

    I was just looking at some specs for a 3.4m stabi-craft type boat. 90kg dry weight, >1m internal beam, 15 HP Max power.

    I've been thinking about the bow issue you mention. I would need lift in the bow but as you note don't want to impede visibility.

    What if I carry the sponsons all the way to the bow that might give me fullness without height. I could also fit a low spray dodger of some sort.

    When I was kid friends had a wahoo wildthing like this.

    It was the opposite of what I'm talking about , short and flat. That thing was phenomenal. You could literally go play in 5 foot surf.
     
  14. IronPrice
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    IronPrice Senior Member

    The nifty boats are an option too but I think I would pop it landing on a gravel beach.
     

  15. Mr Efficiency
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    Mr Efficiency Senior Member

    I am not a salesman for those collars, by the way, or have any stake in the business, but I can see they have some usefulness, particularly where you don't want to add much weight, and improve stability of small craft. You could make your own at a pinch, it is just polyethylene foam, basically.
     
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