Our boat is parked in the back yard for the winter. I have covered our Hunter 240 with a tarp, drained water, etc. With the boat covered, I thought it would be good to open the forward hatch (over the v-berth) just a bit, put the screen in place, and open the aft hatch (at the cockpit) also. This would allow at least a little air to circulate during the hibernation. Are there reasons why I would not want to do this?