[other tom]

I used 3/4" divinycell (essentially same as kledgecell) with 1808 pre-skinned on each side. Longest span I have between stringers/bulkheads is about 6' fore & aft and 38" athwartships. I measured, cut, and assembled the whole floor off the boat on a perfectly flat floor layered with plastic. butt jointed all the pieces together with epoxy & milled fibers, then layered each side with another schedule of 16oz biax. Glassed in some plywood backing in areas like the leaning post and console. Advantage was that the fairing was a lot easier since it was essentially already fair. (this is on a 25'). The whole floor went in (only weighed 42 lbs, 20' long, 7' wide) and glued/tabbed to all the stringers/bulkheads. Shot it with high build, sanded, then 545, and good for the finish coat. Doing the hatches and drainage gutters, thats another story.

I regularly abuse the boat and not a bit of movement. Don't drop anything heavier than a shimano 50 on it from he heigth of the t-top though (also another story) An 80 will require some body work....I have the visible data.