> Using the thicker plywood will significantly increase the weight of the
> boat. The deck will be harder to bend and the hull shape, which is
> dependant on bending the plywood, will be harder to get right. My advise
> would be to exchange the plywood.

> That said, I have a Cape Charles 17 and it's a wonderful boat. It tracks
> well, it's fast, maneuverable stable and comfortable. It always suprises
> me when I get back in it after paddling other boats how responsive it is.

I think you should use what wood you have. What got me hooked on paddling was an 8' kayak that I built from scrap 1/4" BC exterior pine ply. I used a sheet of 1/8" doorskin for the deck. (It's a JAM8, plans in an old Boatbuilder magazine.) My next boat was a CLC 16 using plans from CLC and 4MM cheap okome. I taped the interior seams only and glassed the bottom just between the chines. Before I joined the pieces together I rolled on two coats of epoxy. It's an excellent boat but am now building one of Nick's Guillemot 17's, just because they look so great. (They probably paddle great too.)