I should clarify that my post regards a 36' powerboat. I think this makes a big difference as I have a huge portion of my boat well above water. Temperatures were in the 20's to low 30's.
Last winter I used two 20 amp services. One service
powered a 1200 watt forced air heater (salon) and 600 watt forced air V-berth.
The other service powered a 1500 watt oil
filled heater (salon) and another oil
heater set to low in the V-berth.
At night I used an electric mattress pad as well as the forementioned heaters. I don't really talk to the other residents here, but I noted this morning the harbor was buzzing with the sound of Espar and the like heaters. Also the as the temp drops, the harbor thins out with many people moving in with friends / hotels / etc. This probably isn't a bad idea. Spending a couple grand on off site living is cheaper than installing and maintaining an Espar I am sure.
Wood is a very nice way to heat, but requires a lot of maintenance
to keep the fire going. And stockpiling wood. And filling up the harbor with noxious smoke.
The most useful thing I have found with heating is my remote
This heater has a remote
control device that lets me turn it on and off. This is great when I am cooking
, as I can turn the heater off when I want to use an electric cooking
device. Then when I am done I can turn it back on, all from the galley
, with the heater being located on the other side of the boat. It's really convenient.
This year I don't have the 20amp option, so I may go with two 30amps, or I could get my oil furnace going, not sure which is more realistic. But I strongly recommend the heated mattress pad and the remote control heater. Those work great.