Re: Issues with Heating in Annapolis, MD
One thing we did when we lived on our boat during winter in Annapolis was to wire two electrical outlets from the 30A circuit that is decicated to the Aircondition.
One outlet in the aft cabin, one in the salon.
That way we utiilized all 30A shorepower coming in to the 30A aircon circuit to run two large oil filled heaters, while still having the 30A on the "house circuit" available to run other electricals (TV, toaster, coffe maker etc) on the boat.
You should be able to do the same thing since your boat has two 30A circuits and dual shore power inlets.
If you cannot do the install yourself, a marine electricain (or general handyman) should be able to do this inexpensively.
The two oil heaters kept our boat warm during the entire winter, we never saw less than 66F in the boat regardless of outside temp.
This modification together with a dehumidifier, a froli systemunder the matress and electric blanket was the things that made our winter relatively comfortable.
Other than that, moving into a house might be the best solution ;-)