Man is regressing

Discussion in 'Boat Design' started by kapnD, Jan 30, 2019.

  1. portacruise
    Joined: Jun 2009
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    portacruise Senior Member

    Angel, thanks for the float tube links.

    The tear drop shaped ones can be customized for all kinds of accessories, even including motor propulsion. Mine get a lot more use than I ever had from a proper small motorboat!

    I just wonder how much debris and weed that the progressive foil boats can handle....

  2. sharpii2
    Joined: May 2004
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    Location: Michigan, USA

    sharpii2 Senior Member

    Extreme Beam is not aleways a bad characteristic. Since LWL is typically the greatest limit to speed, we tend to make our boats as long as practical. But when speed is not the main virtue we're after we can go for some rather extreme Beam. This particular boat is clearly intended for very small lakes and ponds where it may have to voyage just a mile or two or less. The wide Beam here gives the boat great initial stability much needed for it's intended purpose--stand up fishing.

    A personal favorite of mine (see attachment) was an attempt to design an extermely capacious 10 ft sailboat. I chose a very diamond shape hull plan. It would probably never sail faster than 3 kts and I probably would have been able to get more interior volume by going with a transom stern. but I found other things to like about this plan. If hit abeam by a breaker, for example, it would be far less likely to be flipped than a straighter sided boat.

    Attached Files:

  3. Angélique
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    Location: Belgium ⇄ The Netherlands

    Angélique aka Angel (only by name)

    Since her full keel runs up to the stern I'm afraid she would be almost as easily flipped as with a transom stern, as she's likely to trip over her keel anyway when hit abeam by a breaker, which isn't dangerous for this kind of small and fully closed boats with a short mast, it is however a great discomfort.
    Last edited: Feb 6, 2019
  4. Rurudyne
    Joined: Mar 2014
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    Rurudyne Senior Member

    The ramform hull design might be thought of as trying to get extreme beam without extreme prow and it's attendant wave system.

  5. sharpii2
    Joined: May 2004
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    Location: Michigan, USA

    sharpii2 Senior Member

    What I really meant was with straighter sides and a transom. As it is, the lack of a transom provides no large, flattish area for the breaker to work against, which is also at a 90-degree angle with the keel. Unless hit squarely abeam, the boat will tend to scoot away. And if hit squarely abeam, the angular sides will tend to split the wave, dissipating much of its eneregy.

    Although the long keel will certainly trip the boat, it will also dampen its roll. By doing so, it will slow the roll down by maybe enough to further dissipate the breaker's energy. Intuitively, its easy to imagine that with no keel the boat would be able to scoot sideways when hit squarely abeam. But with such chines and such a deep "V"bottom, this may not be the case. In fact, it might be carried along before the breaker at great speed then suddenly trip and flip.

    I suppose both scenarios are possible, given differing circumstances.
    Angélique likes this.
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