I built a couple of S&G free plan guillemots for the kids (and myself). They are brilliant little boats and I believe the hard chines help is 'chine steer' very effectively, possibly more so than the strip versions.

I haven't noted any significant 'slapping' and am sure it doesn't slow the boat down ... however it does go down wind fast and well. A chap in New Zealand who built one did a 20 mile down wind run once and overshot his put out bay by 5 miles [didn't have a gps and wasn't familiar with his landmarks] because he was going so fast and having such a good time.

I wonder if the slapping is a combination of the hard flat chines (and bottom) and punching directly through chop. When I am out surfing I tend to punch all but breaking waves at an angle .. that way the kayak doesn't launch itself into the air and slap down.

By the way that will happen with any kayak.

Go for it

Cheers Pete

http://home.clear.net.nz/pages/grantglazer/Kayak/Guillemot.htm