Cleans up the dark streaks and leaves a smooth glossy finish that seems to clean up easily. Still buffed out easily, but I don't recall the slime being any easier to wash off, though I have always waxed the entire hull at least once a year. Good luck and let us know how it works out if you proceed. If you need to make a repair on fiberglass, the silicone will hamper the repair. The repair won't stick.
Silicone is hard to remove.
I clean well with acetone and a clean rag to remove any dirt, grease, wax, etc. Inc. Additionally, this material has not been reviewed by Catalina Yachts, Inc. for technical accuracy. This page's maintainer cannot guarantee the accuracy of this information or the desirability of suggested modifications or upgrades. Please obtain assistance from a competent marine mechanic or boatyard prior to making any significant modifications to your vessel.