Covering your boat in the winter benefits it by protecting gelcoat, preventing snow and ice accumulation, and keeping water from pooling on the decks. More frugal skippers seem to think that a few tarps stitched together with a spiderweb of lines qualify for winter duty.
In the first serious storm, these often end up shredded, and in their death throes they deposit large amounts of snow and ice into the boat they are supposed to be protecting. If you're going to cover the boat, use a custom cover or shrinkwrap it. But either way, make sure there's lots of ventilation to prevent mold from taking over down below.
If you do choose to shrinkwrap, think twice and even three times before doing it yourself. All it takes is a moment of inattention to ignite the shrinkwrap, and if the fire occurs inside the cover, it might not even be visible right away. Every fall we get several claims involving flaming shrinkwrap, often involving multiple boats. This is one job best left to the pros.
BASED ON AN ARTICLE IN BOATUS