RCP's Hull Cleaner is a safe and easy-to-use gel designed to tackle the toughest stains on your boat without harsh acids. Its thick formula clings to surfaces, including vertical areas, giving it maximum cleaning power without running or dripping, which makes it ideal for fiberglass and painted surfaces. Hull Cleaner works quickly to dissolve rust, dried fish blood, leaf stains, and other stubborn marks, leaving your boat spotless and restored. Simply apply it, let it work, and rinse for a sparkling, like-new finish. Gentle on your boat yet tough on stains, Hull Cleaner paired with RCP's Marine Soap and the rest of the marine lineup keeps your vessel looking its best season after season.