Cape Cod
You can't go wrong with the ocean, and the strong sea-faring history of this area provides the nautical theme. If you're an architecture fan, I'm sure you'll find plenty of subjects - from the churches and old industrial buildings in New Bedford, to the Provincetown Tower.
Lighthouses
Plenty of lighthouses in this part of New England too, but the trip around Cape Cod may expose you to the most, in the shortest amount of time. None that I have visited are in any remote areas (is there such a thing in Massachusetts?)