Oxidation
Test for oxidation by wiping a bit of your wax on your boat with a clean rag. If you see chalk or paint coming off on your rag, you are oxidizing. You must reverse the damage or it will cost you a tidy sum to repaint or reseal your boat.
You need to remove the oxidation the grab a bottle of Mary's RenewzIt RenewzIt is formulated to remove oxidation, scratches, and water marks. Wait 24 hours giving RenewzIt time to cure.
Then apply Advantage to protect from further oxidation.
Oxidation can be caused in several ways: The use of a silicone product; a low grade petroleum distillate in a wax; carnauba wax; not waxing frequently enough and not cleaning the boat often enough allowing scum and dirt to deteriorate the finish.