Marine Grade Plywood?
Jeff, I''ll look at the dix boats shortly...
Wish I could afford the marine grade plywood, but not likely to happen for me.
Now, some thoughts...
Sounds like I could retain my double hull idea and perhaps reduce the weight if I went to 2 layers of ply for the outer hull and a single layer for the inside layer.
I had considered the problem of running up on a snag/rock, whatever... I suppose I could sheath the bottom in light gauge steel... maybe 18 gauge. Seeing as the boat would come out of the water after each use, touching up the bottom paint to keep the steel safe from the water would be no big deal and the steel would also toughen up the lower hull mitigating the reduction of the outer hull to 1/2 inch total ply.
I''m guessing the steel would go on the outside of the resin layer to protect everything under it. The steel layer would only add a couple hundred pounds at most as 18 gauge is pretty light stuff, but likely more than enough to repel minor collision punctures.