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Seeking: Resistance vs stability *PIC*
By:Kudzu
Date: 8/5/2010, 11:54 am

Playing with a new design and while playing with different version I ran into something I just want to hear other peoples input on. I don't think there is a right or wrong answer. I am just looking at the balance between stability and resistance. I created a chart showing the different versions of the boat and listing the SF for each one.

This is hard chined Greenland style boat. 15.5 ft on the water line and it started at 18.5" wide at the water line.

Then I rescaled the width of the boat to 97% and kept doing that with the different versions. So this is basically just a narrower version of the boat.

Version 1 is Fairly stable but probably not a first timers boat at 92, then V2 drops to 82, V3=79 and V4= 76.

I charted the different versions. Speed in knots is on the left. Lbs of resistance is along the bottom. Looking at the difference in resistance the gain in (potential) speed is minimal. Most of the gains are in the racing, real strong paddlers and sprinting speeds. So for less stability it appears you gain minimal advantage. Version 2 seems like the best compromise to me.
BTW, the blue line is a multi-chined hull. I wanted to compare it too.

Of course I realize there are other reasons for less stability and yes I know there are many more factors in the design of the hull. This was the first time I had actually compared these and was a little surprised at the numbers. Just want to hear others opinions and thoughts. Bound to lean something.

Here is the description from Killen of his Stability factor numbers.
110+ is comfortable for all novices
100 is comfortable for most paddlers
98 will be initially tender to some novices, but after a few paddles will be quite comfortable
92 is not comfortable to most novices.
88 is a challenging boat for some people to paddle
40 to 50 is the low end, a K1 racing kayak would be somewhere in that range.

Messages In This Thread

Seeking: Resistance vs stability *PIC*
Kudzu -- 8/5/2010, 11:54 am
Re: Seeking: Resistance vs stability
Robert Livingston -- 8/8/2010, 6:06 pm
Re: Seeking: Resistance vs stability
Kudzu -- 8/8/2010, 9:36 pm
Re: Seeking: Resistance vs stability
Kocho -- 8/8/2010, 9:29 am
Re: Seeking: Resistance vs stability
Kudzu -- 8/8/2010, 10:46 am
Re: Seeking: Resistance vs stability
Bill Hamm -- 8/8/2010, 2:01 pm
Re: Seeking: Resistance vs stability
Kocho -- 8/8/2010, 4:03 pm
Re: Seeking: Resistance vs stability
Bill Hamm -- 8/9/2010, 12:44 am
Re: Seeking: Resistance vs stability
Bill Hamm -- 8/6/2010, 1:36 am
Re: Seeking: Resistance vs stability
Kudzu -- 8/6/2010, 5:03 pm
Re: Seeking: Resistance vs stability
Bill Hamm -- 8/7/2010, 2:01 am
Re: Seeking: Resistance vs stability
Mike Savage -- 8/6/2010, 7:38 pm
Re: Seeking: Resistance vs stability
Kudzu -- 8/6/2010, 9:10 pm
Re: Seeking: Resistance vs stability
Bill Hamm -- 8/7/2010, 2:05 am
Re: Seeking: Resistance vs stability
fred graus -- 8/5/2010, 2:20 pm
Re: Seeking: Resistance vs stability
Kudzu -- 8/5/2010, 3:31 pm
Re: Seeking: Resistance vs stability
fred graus -- 8/5/2010, 4:18 pm
Never could proof read my work :-) *NM*
Kudzu -- 8/5/2010, 4:22 pm