I have put graphite epoxy coatings on the bottom of my Pygmy Arctic Tern and Osprey HP. The sand, limestone, and oysters here in Florida really take a toll. Prior to the graphite application, my Arctic Tern bottom showed a lot of scratches and gouges. With the graphite, my boats show less damage, but still some scratches and gouges. It took 3 coats to get a solid black finish. Then I wet sanded the bottom, progressing to 600 grit.

I use MAS epoxy, purchased from Chesapeake Light Craft, because it sets more slowly in the Florida heat and because it is less viscous and flow better.