On Wed, 31 Oct 2007 10:00:31 -0700, Sunk wrote:

Whats a good wood to use? Ideas?????

Cedar is light and rot resistant.

3/4 inch ply is on the heavy side for flooring in a 20 footer in my
opinion. It depends on how well it's supported of course. If you
want the boat to last, spend the extra money for marine plywood. It
has fewer voids and is stronger.