Boat Building Forum

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Re: Strip: Short and narrow design
By:Allan
Date: 10/14/2011, 5:08 pm
In Response To: Re: Strip: Short and narrow design (Jeff Horton)

When you shorten the waterline length of a kayak, you usually reduce the wetted area, so the effort to paddle at lower speeds is reduced. It will usually be lighter, so it will accelerate off the line more quickly.

However once speed increases, it reaches the paddler's limit sooner.

Another change that I don't think anyone has mentioned is that if you simply shorten the kayak you lose stability. A big reduction in length can have a dramatic effect on stability.

As an indication of how significant this can be, I took a fairly standard 5.2 metre sea kayak design which had a SF of 96 and a maximum righting moment of about 15 with a 150lb paddler. Reducing the overall length to 4.2 metres reduced the SF to 77 and the maximum righting moment to about 11.5.

That is an enormous difference. It would need over an inch added to the beam to restore the original stability.

Those figure refer to the overall dimensions, not the waterline dimensions, but I think they illustrate the problem.

Messages In This Thread

Strip: Short and narrow design
Robert Shapiro -- 10/13/2011, 3:40 pm
Re: Strip: Short and narrow design
Glen Smith -- 10/13/2011, 4:18 pm
Re: Strip: Short and narrow design
Robert Shapiro -- 10/13/2011, 4:42 pm
Re: Strip: Short and narrow design
Glen Smith -- 10/13/2011, 5:21 pm
Re: Strip: Short and narrow design
Bill Hamm -- 10/13/2011, 7:00 pm
Re: Strip: Short and narrow design
Jeff Horton -- 10/14/2011, 8:22 am
Re: Strip: Short and narrow design
Bill Hamm -- 10/14/2011, 8:33 am
Re: Strip: Short and narrow design
Allan -- 10/14/2011, 5:08 pm
Re: Strip: Short and narrow design *PIC*
Jeff Horton -- 10/14/2011, 5:44 pm
Re: Strip: Short and narrow design
Brian Scarborough -- 10/14/2011, 7:30 pm
Re: Strip: Short and narrow design
Brian Scarborough -- 10/14/2011, 7:33 pm
Re: Strip: Short and narrow design
Bill Hamm -- 10/14/2011, 7:53 pm
Re: Strip: Short and narrow design
Allan -- 10/14/2011, 8:11 pm
Re: Strip: Short and narrow design
Stephen Troy -- 10/13/2011, 4:54 pm
Re: Strip: Short and narrow design
Robert Shapiro -- 10/13/2011, 5:26 pm
Re: Strip: Short and narrow design
Etienne Muller -- 10/13/2011, 6:42 pm
Re: Strip: Short and narrow design
ancient kayaker -- 10/13/2011, 7:18 pm
Re: Strip: Short and narrow design
Etienne Muller -- 10/14/2011, 8:51 am
Re: Strip: Short and narrow design
Charles Robinson -- 10/13/2011, 7:43 pm
Re: Strip: Short and narrow design
Nick Schade - Guillemot Kayaks -- 10/14/2011, 10:03 am
Re: Strip: Short and narrow design *PIC*
Yostwerks -- 10/14/2011, 10:36 am
Re: Strip: Short and narrow design
Yostwerks -- 10/14/2011, 11:36 am
Re: Strip: Short and narrow design
Charlie -- 10/14/2011, 11:42 am
Re: Strip: Short and narrow design
Yostwerks -- 10/14/2011, 11:53 am
Re: Strip: Short and narrow design
David Bynoe -- 10/14/2011, 3:52 pm
Re: Strip: Short and narrow design
Etienne Muller -- 10/15/2011, 10:20 am
Re: Strip: Short and narrow design
Mike Savage -- 10/15/2011, 2:34 pm