How do I clean bumper marks on fiberglass hull

[Jimwhall]

The lake is low this year, and I can't seem to get the bumpers high enough. The boat has been bumping into the doc mounted bumpers but they have left a white residue on the hull. I'm new to fiberglass and gelcoat. Any suggestion on cleaners that won't damage the hull?

 

[briangcc]

Rubbing compound followed by a liberal coating of wax will work.

Some manufacturers market a "cleaning wax" which is an all-in-one solution....rubbing compound and a wax. May or may not work for your specific application.