Kayak stability can be a bit complex. As Bill pointed out virtually every hull measurement and shape can affect stability, and the different weights and positions of the paddler will change stability no matter what the hull characteristics. So will the amount and positioning of any cargo.

My suggestion if you really want to pursue this is to get a copy of Kayak Foundry, read the stability information on it, and play with hull shapes to get a feel for how stability works. The stability graphs will likely do more to increase your understanding of what stability is and how it is affected by loading and hull shape than other kinds of information will. Also, I seem to recall that someone mentioned that the program can now be tweaked to allow stitch and glue or skin on frame shapes, so you may be able to design your next build with the program, and know what the comparative stability characteristics are before you build it.

Good luck,

Allan Edie

will : Ok, so I have two kayaks in Ontario that I built from Yostwerks
: plans (one glued and the other lashed) and was happy very happy
: with the way they paddled. Then I did three in Newfoundland, 1st
: with Instructables plans and by the forth no plans. Both were
: beautiful works of art. Unfortunately they where both very
: unstable (my own design better but still...) and didn't get used
: much at all. I did a fith one aswell, also my own design which I
: was very proud of. It was designed for someone for fishing. It
: was extremely stable (at 24" wide you could stand up in it)
: but I managed to preserve the very sleak, sporty profile (not
: boxxy) and somehow still maintained great secondary stability.
: It was to be outfitted with adjustable foot braces and
: comfortable seat so anyone could jump in and go. This design is
: not what I want for myself as I spend alot of time rolling. I am
: now in BC and very excited to start working on another but am
: desperately seeking the secret ingredient. I am not expecting to
: go on weekend trips, just something for day trips and rolling
: practice. I love building and don't mind doing a few but I spent
: more time building than paddling last year and am anxtious to
: get back on the water. Especially being on Salt Spring Island.
: All five boats are so very different and not with me so I can't
: give specs on all of them. I will say though that the ribs on my
: instructables boat ended up too rounded and the depth ended up
: two inches deeper than planed and so i fixed it by lowering the
: knee brace two inches (it was raised Two inches so I brought it
: flush) and I realize that was a mistake and should have redid
: the ribs. For the next one I opted for 1 1/2" ribs and less
: of them so I could focus on shaping them better (the wood there
: was terrible) but it was still hard to keep upright unless you
: where really moving. And yes I was looking at the shear depth
: and it seemed like it was going to be great...
: I am hoping someone else has encountered this problem and found a
: fix and can help me out. It is really embarassing to have
: everyone ohh and ahh your boat but never see you in the water.