I keep my boat on a mooring for 90 days each summer. Even in the ADK there is a lot of sun. I fear this is damaging my sail, since I leave the main on the boom, tied up with bungee cords. I can put on a basic sail cover, as the sail is detached from the mast and loosely rolled. Or I could put on an awning or canvas that extends down to the rails of the hull. Which is better? Anyone do either of these?