A good paint.
While working as a civilian contractor on a guided missle cruiser, I noticed some of the seamen on board were painting the ships powered, fiberglass launches. I asked what type of paint they were using and was told it was a common, commercial grade polyurathane paint.Over the course of the few days I worked on the ship, I saw them sand, prime and paint the launches. I was very impressed with the results and priced the paint at a paint store. It really isn't that expesive for the results you get. I'd recommend a good quality Polyurathane.Mike