ZING Marine Safe Boat Hull Cleaner safely removes marine deposits, scum, oxidation and algae. Non-fuming, easy to apply and use. Removes stains and discoloration on boat hulls. Ideal for fiberglass, painted wood, metal hulls, exposed power drives and propellers. Effective on boats used in both fresh and salt water. Attacks & loosens zebra mussels and barnacles. Marine Safe Boat Hull Cleaner is non-hazardous for people and marine environments. VOC Free with no harsh chemical fumes.