I have had this boat since 2007. I have never been able to truly remove all the water spots from the cowling. Found a bottle of Marine Shield restoration compound and was buffing a few spots on the hull cap and thought I would hand rub the cowling to see what it would do. It took the spots off instantly and it looks like a bright shiny new Cowling.
I would add a picture, but can't take one with small enough data to load up anymore.