In the Sept / Oct 2009 BoatU.S. Magazine (Page46) there is an article titled "How to Repair Deck Non-Skid".
MAS packages (12" x 12" square) of "Flex-Mold" in a tube with instructions are available @ West Marine. Larger pieces can be obtained directly from MAS @ www.masepoxies.com / 856-303-9245.
For great tips, and more details and photographs about this project to to www.boatus.com/magazine