The best description of I've read about these typse of hulls was in a catalog from the We No Nah canoe company. It may not have been the most comprehensive explanation, but it was in simple words, and had pictures. It spared me from the usual jargon.

I don't know if that catalog is still around, but there are articles on hull design on the net. And We No Nah has a nice website. You should also check books on canoes and kayaks at your local library and bookstores.

From what I have gathered:

The idea behind these hulls is to increase speed, or reduce drag -- which is the same thing in my book. Racing canoes, which compete in categories that place limits on the overall length and width, have evolved into some of these strange shapes.

If you are not competing in a particular class, but just using your boat for recreational use, generally, if you want a faster kayak, you just have to make it longer and thinner.

Hope this helps

Paul Jacobson