To give fiberglass a smooth, shiny surface during manufacture a material called gelcoat is applied first into the female mould for the boat and fibreglass mat is laid over it and the resin is sprayed or rolled onto the mat. When the boat is removed from the mould, you’ll see the gelcoat surface over the fiberglass mat forming the outer skin of the boat. However, most people refer to gelcoat as fiberglass, so we use the terms fiberglass and gelcoat interchangeably.Gelcoat is available in many colors and is fairly durable, but it can become dull or faded as it weathers. Sunlight and air combine to oxidize the gelcoat surface, fading it and making the surface cloudy. The oxidation process for gelcoat is similar to how metals rust or corrode. So how do you keep your gelcoat looking good? Simple: you coat the surface with either wax or a polish/sealer.