This winter, I'm keeping my bass boat out side due to my son's truck restoration.
All of my friends and my boat dealer said to put a hand full moth balls on a plastic plate in several locations in the boat. They also said to put down a bunch of mouse traps in all of the compartments before placing the cover on the boat for the winter. I hope this helps.
Do you have any idea how hard it is to pull all of those moth's balls off???