Most of the sailors has a ceremonious preparation against sun before going to the water. Choose the right lycra or spandex top, sunglasses, hat, and some waterproof sun cream to the nose at least. Because you have to protect yourself from the sun's harmful rays. The tans what we all needed not so long ago have been mostly replaced by the desire to avoid skin cancer. OK, but your skin is not the only thing that needs protection from the sun! What about your loved boat? What are you doing to protect it from the sun, especially on regatta days or long training sessions? To preserve its showroom shining and maintain its resale value?
Boat builders call the outer skin of a fiberglass hull and deck "the gelcoat". It is actually an extremely thin layer of pure resin. Contained in it is the pigment which gives your boat's characteristic color. You may think you own a white boat, but what you actually have is a really thin layer of white gelcoat, haha. Or blue, or red, choose your colour....
In a cosmetic sense, gelcoat performs the same function as paint on the sheet metal of a car or on the wood of a table. It provides a glossy, colorful finish that is pleasing to the eye. But, the gelcoat does more than just look good. It also seals the fiberglass layers beneath it against water or moisture.
Ultraviolet light is a real monster here. It bleaches the pigment and causes the outer surface to turn chalky and unglazed. The tiny cracks appears, and the slow horror is starting, what in the very distant future kills the boat. So keep your boat under a good cover, what protects it from the UV rays, and protects the gel coat finish from the sun.