We are in Tasmania, 43 deg. South, approx. We came into a marina for the colder part of winter. We bought a de-humidifier rated at ten liters per day. (Actually, two of them, but that's another story.) We have taken thin clear pvc, and stuck it on the inside frames of all the opening ports
and hatches. The previous owner put in spray insulation
in the inside of the hanging locker and low overhead spaces in the forepeak and the head
. With the de-humidifier, we no longer have the rainforest we had last year, and that is a huge improvement. The electricity for the dehumidifier and the little electric heater ran about $50 last month.
As to heat, we have a Dickinson
copy called a Fab-All, a diesel, burner type heater, and there is a small computer fan mounted on the overhead, to encourage the warm air towards the cabin sole
. We do not have a genset, so we use a hot water bottle instead of an electric blanket. On the colder mornings, when there is snow nearby, we also use a cheap electric heater to blow air under the table where our feet usually are. We are able to be warm enough this way. If you are used to winter in Maryland, you will already have adequate clothing
for the conditions, and probably do a way better job of it than we, tropically acclimated, did.
Jim knew, and I was surprised, how very much difference the de-humidifier has made. There has been no rain forest in either aft cabin (a long way from the heat source.)
Some friends of ours who sailed from here to Alaska
and return insulated all their cupboards, and created a clear plastic cockpit
enclosure, except for the top of the dodger
, which is opaque, for sun protection. The "crystal palace" not only creates a warmer space, it really extends the working/living area, and it is nice to be able to see out. We have two sets of friends with "crystal palaces": one had theirs made to their specifications, and the others have made both dodger
, frame, and enclosure themselves. It is a big project
when you start from scratch, but you get to make it just the way you want it. Besides the warmer space, it also gives you somewhere above decks to put wet foul weather
, and other gear
Good luck with it.