A boat is a seasonal vehicle and, while you may get a lot of use from it during the summer, it generally stays in storage for the winter. But storing a boat for six or more months involves adequate protection that should repel UV rays and keep out moisture and water, which will create mildew and dry rot. Popular methods of protecting a boat during the winter include shrink wrapping, tarping a boat, and storing it in a portable garage.
Shrink wrapping a boat is similar to shrink wrapping for any other product, but the primary downside of shrink wrapping a boat is its lack of breathability. The typical material is a plastic, flame-retardant UVI (UV inhibitor) which, when used with heat shrinking or welding methods, seals in moisture. Although the material is somewhat better than not protecting a boat, the sealed moisture will lead to mildew and dry rot. In addition, a heat shrinking package for a boat costs about $200 for storage for one year.
For the most economical option, tarping a boat with a heavy-duty poly tarp is your best bet. Although the tarp will typically last one winter, its durability to the elements will protect your boat. Polyethylene, as a material, is a breathable material will keep out moisture but, due to a high dernier of fabric weave, the polyethylene will also keep out moisture. In addition, a heavy-duty poly tarp is often UV treated and will protect the paint from fading and surface material from cracking.
A long term option for protecting a boat is a portable garage. A portable garage can store other vehicles during the year but the structure is breathable and, like a tarp, is UV treated, as well as anti-fungal treated, and will keep out water and UV rays and will allow for air circulation.