Star Brite® Bottom Cleaner, Gallon. Removes deposits on boat bottoms, scum line and rust stains quickly and easily. - Water based, environmentally friendly, biodegradable formula. - Special patented buffering process makes this product safer than other acid based bottom cleaners. - Safe for use on fiberglass, metal, wood and stainless steel surfaces - Also great for removing rust stains - Begins working on contact Ideal for removing marine deposits from inflatable boats and RIBs