Do you want to paint the complete hull or just a spot? As long as you work on spots and the boat has gel coat and not paint, I would recommend gelcoat. I know only German brands, hence I can't give you gelcoat you can buy in US.
Usual gelcoat need to be covered by a plastic film or you have to mix wax in it. If not, the surface remains sticky. Takes about 24h to cure and surface needs to be sanded. There are two sorts of polyester gelcoat, one is only applicable for non permanent water contact. There is also epoxy gelcoat, which is more resistant but also more expensive.

We have no booth as well, but a small party tent helps on windy days.

Cheer,

Klaus