Re: [Paddlewise] chine and stability

From: ralph diaz <rdiaz_at_ix.netcom.com>
Date: Wed, 15 Nov 2000 10:46:31 -0800
Matt Broze wrote:
> I didn't word that quoted passage very well. What I meant to get across was
> that the further the kayak could be leaned before reaching maximum stability
> the more likely an expert kayaker would say it had good secondary stability.
> By my definition even a very unstable kayak can have good secondary
> stability as long as the point of maximum stability is shifted enough to the
> right that a kayaker can't easily lean the kayak beyond it. This is far
> different than the "overall stability" (the total energy required to cause a
> capsize) which can be measured by measuring the area under the curve. This
> feeling of secondary or final stability to a kayaker takes in to
> consideration that the kayaker wants to intentionally lean her craft. Low
> initial stability allows this to be done easily so there is no big hump that
> has to be overcome to get the kayak leaned to there but an even further lean
> would be resisted by a still increasing righting force.
> 
> Once beyond the peak righting force it is hard to stop a capsize because
> each degree further you lean the less the stability becomes. 

Secondary stability means different things to different paddlers and,
Matt, your description really sheds a lot of light on this.  As far as I
can tell, secondary stability is something that a better paddler can
take advantage of for sculling, leaned turns etc.  But it would be a
mistake for a less able paddler to think he or she has some level of
stability that will kick in to keep them upright after they move from
initial stability to this "secondary" stage.  It really is only there if
you have the abilities.  In a part that I snipped from your writeup, you
wondered out loud whether Sea Kayaker might want to add a component to
the stability curves that reflects what a more expert paddler would do
with his or her body to control the boat at this secondary stability
stage.  Your thought on that underlines how closely related the
"stability" of the secondary stage is to the actions/skills of the
paddler.

ralph diaz
-- 
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Ralph Diaz . . . Folding Kayaker newsletter
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"Where's your sea kayak?"----"It's in the bag."
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Received on Wed Nov 15 2000 - 09:41:35 PST

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