If you've ever wondered if you could use car wax on a boats gel coat. I found this on the Meguiar's site, in the FAQ section.

Q: WHAT IS THE DIFFERENCE BETWEEN AUTOMOTIVE WAXES AND MARINE/RV WAXES?
A: Meguiar's Marine/RV products are specially formulated for gel coat and linear polyurethane (LP) surfaces, which are chemically different than automotive paints. Modern gel coats and LP coatings are harder and more water resistant than automotive paints. Their unique chemical compositions demand special ingredients that are specific to these marine uses and formulated for use in marine environments. Automotive products will not achieve the same high quality results on boats or RVs.