Yeah, Kev2809 marine plywood is the original product on panel truck floors and it does stand the test of time very well.
Hey, olblue60 are you going to use marine ply or have you thought of anything else as a substitute? Just curious 'cause I'm looking for ideas for my floor. I can't get the 9 ft length around here and the shipping would be killer although Arad68's link was informative.
Marine trees.............funny stuff