Hi Alan:
Thanks for the links, very encouraging. Now I will check wich kind of plywood in 3 mm is the best suited for a canoe. Hopefully one with three layers of equal thickness, there are some poor quality ones with thinner surfaces and thicker inner core that does not have any structutral resistance.
3 mm is also easier to cut by hand with a japanese saw OKUMA!!, great.
Tato. Lazo.