I replaced the floor in my Koffler summer before last. I also had a hard time trying to figure out what to use. I thought about the Diamond plate but I didn't want the extra weight in the boat. I decided to use half inch marine plywood. I coated it with a Marine varnish. Right after I had applied the Varnish, I sprinkled some of that sidewalk sand stuff (I forget the name of it) on the wet surface of the varnish. It adhered to it remarkably well. It turned out so good I can hardly believe it and I think it will last a long time...I hope this helps...