We spent two summers in Maine and Nova Scotia, in cold water, and
got some mildew from condensation under the aft cabin bunk, over the
settee refrigerator, and in a few other places. We also got
condensation anyplace the cold hull is exposed to the interior of the
boat, for example the floor of hanging lockers. Two suggestions:
1) Buy some HyperVent material and place it under all bunks and under
the cushion over the fridge (www.hyperventmarine.com) This stuff is
great at preventing mildew from condensation. You can also line the
bottom of lockers that are in contact with cold water with HyperVent.
2) If you do get mildew on the "carpeting" material under the
cushions, for example under the aft cabin bunk, spray some bleach and
water(50-50)mixture on it, brush it in well, and let it sit for 30
minutes, then rinse it off and dry well. We have found that this
removes all mildew without damaging the carpeting.
Roy on Excalibur SM #195