Re: [Paddlewise] Easy to Roll = Easy to capsize

In a message dated 12/28/99 4:23:34 PM, CHUCK_at_multitech.com writes:

<< Speaking of rolling, Bob Brown, a canoe designer, thinks a kayak that is
easy to roll is necessarily also easy to capsize (Bob does not paddle in
big waves). I disagree. Comments?>>

    First the disclaimer:  I don't know Bob Brown or Chuck personally.  So 
this is not intended to offend anyone.  Please forgive my ignorance if I step 
over the line.

    I'm not sure what the logic is here...maybe a case of transductive 
reasoning.  Boats that are hard to capsize, like a Folbot, can be impossible 
to roll.  While high performance boats like the Romany are relatively easy to 
capsize and roll.
    IMHO the ease of rolling is a combination of the overall width, amount of 
shear (more is better), the transition across the deck to the gunwale 
(rounder is better) and height of the combing relative to the hips (lower is 
easier, less restrictive).  Of these only the overall width would have an 
effect on the boats ability to capsize.  The real capsizability of a boat is 
determined by the hull shape (round is best with the paddler above the center 
point). So while technically Mr Brown is right, such is the fact due to 
causes not related to rolling, but present for rough water performance 
reasons in boats that roll easily.
    It boils down to this - high performance boats intended for rough water 
are designed with low initial stability to minimize the righting force 
applied by large and steep waves.  It is expected that they might capsize at 
some point because of these conditions. These boats are normally designed to 
be easy to roll because in these conditions a roll is the preferred rescue, 
sometimes the only possible rescue.  So here is an example of a boat that is 
easy to capsize and easy to roll.
    But it is certainly possible to design a boat with a more stabile hull 
that still has  all the easy of rolling design features mentioned above. 
...hmmmmm  the ideal beginners boat?  Maybe I should contact some the 
designers on this list for a job.

Thanks for the idea.
Jed "the yankee hillbilly"


    On the other hand, you could take a very stabile boat and fit it with 
some 130# of lead ballast centered below the seat.  Then you could have a 
boat almost impervious to capsizing that would practically right itself.  
Like a weeble.  You know "Weebles wobble but they don't fall down" ??

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