Re: Rodent and Insect Protection.
I've had very good luck with moth balls. Don't be cheap, buy a few boxes and set them around. They can be put in open containers like old tupper ware, flower pots, paper cups, etc. Just don't let them sit directly on vinyl, carpet, gel coat, etc because they can "melt", warp or discolor some plastics over long exposure.
Where I live there are racoons, mice, voles, squirrels, rats, ants, etc and it seems to keep everything away except wasps and hornets.
If you can't smell the moth balls from 15 feet away from the boat with the cover on, you didn't use enough.