The only place I saw it used on a boat was on leaky decks and cabin roof and it solved both problems.They did put a coat of latex enamel on top. It looked great. . Captain Al Pilvinis "M/V Driftwood"--Prairie 47 2630 N.E. 41st Street Lighthouse Point, Fl 33064-8064 Voice 954-941-2556 Fax 954 788-2666 Email yourcaptain@earthlink.net Website http://home.earthlink.net/~yourcaptain