I am keeping my boat on a lift this winter (with a roof over the whole boat). I winterized it, put the boat cover in place, then secured a plastic tarp from Home Depot over the whole boat (tower & boat). I wonder if the tarp will do more harm than good. The tarp will protect the boat cover and prevent the sun from damaging the uncovered sides of the boat, but I am concerned that it might trap moisture. Maybe I should cut a hole in the top to permit air to circulate better. Anyone have experience covering their boat with a tarp?