... Boat covers help to protect against damage from snow, rain, wind, and sun. ... The material and fit are vital to protect your boat as well as the cover itself. ... Wood can become dry and this causes shrinking that leads to open seams and cracking. ... The opposite problem is water penetration of the boat material. ... Fiberglass that has cracks or other entry points will become water logged and heavy. ... That leads to further damage when exposed areas allow even more water to enter. ... Without this feature, trapped moisture cannot escape. ... That’s why most boat covers are made of cotton. ... This allows the material to swell when exposed to moisture and this swelling causes pores to close and prevent water from entering. ... Uncoated cotton is also nonabrasive and this allows the boat cover to be installed down to the waterline without scuffing and damaging the surface. ... You also need a frame to support the cover so it can shed snow and ice. ... You can also find ready-made systems for popular boat designs and these do a good job of protecting your boat ...