Re: [Paddlewise] Efficacy of Sponsons on Canoes and Kayaks

Well said, John.  I agree the value of dynamic stability eluded her.

I also was disappointed at the superficial nature of the report.  The money
could have been better spent if the author had more knowledge of canoes and
kayaks, going into the study.

It seems clear the originator of the devices had a major role in making this
study happen.  I hope its results are used wisely.

--
Dave Kruger
Astoria, OR
----- Original Message ----- 
From: "John Winters" <jdwinters_at_eastlink.ca>

[snip]

> Ms O'hara's report disappointed me. When interveiwed I suggested that she
> also interview experts on seaworthiness (naval architects and, in
> particular, Dr C. J. Marchaj) and review the latest literature to learn
the
> technical reasons why paddlers should excersize caution before subscribing
> to the safety claims for sponsons. She did not and her report lacks any
> technical support. I also suggested she visit the Givens Life raft web site
> to see the perils of high initial stability and light displaceemnt but I
see
> she did not include that in her report possibly because her lack of
> technical expertise would not reveal the connection.
>
> In my interview with her I recall clearly pointing out the adverse
> relationship between dynamic stability and displacent as wll as the dnagers
> of considering only static stability as a criteria.and yet she made nothing
> of that in her report. She attributes the stability of canoes to
length/beam
> ratio alone completely missing the point. She does acknowledege that her
> study was not scientifically rigourous and as such I have to wonder "why
> bother?"
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