This is a big question but the answer depends on how you intend to leave/use your boat while in the frigid northeast. We store our boat out of the water during the winter in RI. Prep. includes displacing all engine
, same for other saltwater systems such as AC units, water maker etc; draining engine exhaust
risers - (you may need to drill/tap and insert drainplug); draining all freshwater systems including water heater, washing
machine etc. and flushing
lines (not tanks) with antifreeze
; and flushing
all drains, sumps, and bilge
pumps with antifreeze. On a 50ft trawler
, we use approx 25 gallons of antifreeze!!
On the other hand if you plan to keep using the boat through the winter , I guess all you can do is keep it heated well enough to avoid freezing!!
Hope this helps,