Thanks. I was thinking of getting one like an ADCO, not like a poly tarp. The only reason I was thinking of it is because I live near a coal power plant and the fine coal dust gets all over the roof etc.
Considered covering ours at the season lease site, but as pointed out there is more downside to covering than there is to not covering. I decided not to.
Easier and cheaper to clean the roof than it is to repair the gel coat.