boat cleaning

[Goooh]

This is a loaded question.

How fresh is your boat wax? Do you care to wax the entire boat ever, or just wash it with household products?

If the wax is fresh then use a harsh lifter and rewax the area, otherwise it will oxidize and hold stains even more.

If you have no wax then lift the stain with a harsh lifter then rewax the entire boat.

An ounce of prevention is worth a pound of cure, so once you address the stains go ahead and keep it waxed so the stains never get a chance to really set. Then, never clean with harsh chemicals that strip wax (even dish soap strips it off) and the stains will have a hard time finding a home.