Answer:For your convenience, I’ve highlighted the hyperlinks. Click on the hyperlink to get more information about the selected product.Aurora Waterline Stain Remover
is inhibited so it will not damage your gelcoat. You can use it as often as you need to. If you need to use it more than once a year, I suggest that you protect the bottom with VS721
It will seal the pores of the gelcoat and if the staining is caused by chemical pollutants in the water, it will accept the stain, not the gelcoat therefore protecting the boat. It will also seal the pores against water penetration and osmosis blisters. It's pretty cheap insurance.
Thanks for your question,