Lived aboard several winters in southeastern Mass. Your first problem is finding a marina that will allow you to
liveaboard in the
winter. You'll need one that either has deicers in place, or will allow you to install one in your slip. Having achieved that, you'll need to be certain your
cockpit drains,
engine intake line, etc. will not freeze. That can be a problem even if the
interior of the
boat is heated. I
solved this on one boat by keeping an ordinary incadescent lightbulb on in a drop light in the
engine compartment which was also where the
cockpit drain hoses went down. For
heating I recommend
electric heaters, but there is always the possibility of
power outages. They are simple, dry, and have limited fire
danger if installed correctly. If you are there onboard
diesel heating can
work, but you don't want to leave that on when not on the boat for long periods. Still, the average
fiberglass boat has no
insulation and will sweat like crazy on the inside just from your breath, and it will be hard to heat. A lot of people build a complete cover over the whole boat, which helps a lot, but you still get sweating from the hullsides. One of the strange problems I found is that
marinas will turn off the
water on the docks so you need to carry
water to the boat unless you can rig up a long hose from a spigot ashore somewhere. We found
marinas where we could take showers ashore in the
winter to keep all that moisture out of the boat.