A boat's gelcoat is the outer skin of the fiberglass hull. A layer of pigmented resin, the gelcoat protects the surface of the boat, sealing the fiberglass beneath from the elements including water, moisture and the sun's ultraviolet rays. The gelcoat also gives the boat its color and provides a glossy finish, much like paint on a car.
Damage occurs to the gelcoat simply by being in the harsh marine environment, particularly from the sun's damaging ultraviolet rays. Oxidation of the gelcoat can occur, which gives the boat a dull, chalky appearance. Depending upon the level of oxidation, different tactics must be used to restore the boat, but in most cases, oxidation of the boat's gelcoat is easily remedied.
While the sun is the gelcoat's worst enemy, care must be taken to protect it from water and abrasion as well. Abrasions can occur simply when dirt is ground into the deck, or through nicks and dings from bumping against piers. A worn or scratched gelcoat can allow water to permeate the fiberglass, causing serious damage over time.
The best plan of action is to clean and protect your new boat from the start using a simple gelcoat maintenance plan. Because the gelcoat maintains the integrity of the fiberglass beneath it, and gives your boat a shiny, well-maintained look, attention to cleaning and protecting the gelcoat will preserve it for years to come. If you purchased a used boat with an oxidized or damaged gelcoat, or have fallen behind on your boat's maintenance, fortunately repairing and restoring a boat's gelcoat is easy in most cases.