All-Off Hull/Bottom Cleaner - 32ozRemoves waterline, algae, rust and gas exhaust stains from your boat's bottom and hull areas instantly. Softens barnacle rings and zebra mussels for easy removal. Will not harm fiberglass.Features:Removes waterline, algae, rust and gas exhaust stains from your boat's bottom and hull areas instantlySoftens barnacle rings and zebra mussels for easy removalWill not harm fiberglass