Greg,

Another thing to consider is stiffness of the plywood. If you are doing a complex S&G like the Guillemot S&G then you want very flexible wood. Look at your design, and talk to your wood supplier to find out what would work best. When I had questions, Edensaw was very helpful. They are right down the road from Pygmy (they are their supplier) so they are very familiar with kayak building.

Mike