You may want to use a small handheld GPS, like the Garmin 76 as a back-up. It's very easy to get lost in the fog. The islands and Islets start to look the same.
Lobster pots are almost everywhere. You may want to carry snorkel/dive equipment, including a wet suit. If you get hooked, with sun is going down, you will be on your own.
Spur cutters on your prop may help, but they are not fool proof. They are a court of last resort thing.
Bug spray for sure, at sunrise and sunset in the summers. As far as calling someone, the most recent edition of Taft's is pretty good. We've found that most marinas
don't answer VHF as much as they will their phone #. Radar is a good addition. Without it, you may sit for a spell in dense fog. We have traveled many times by
instrument alone along the coast, using chart plotter and radar. A fog horn, pre-set for the appropriate signal, is useful. A tow service contract is not a bad idea.
I think the last service stops in Penobscot Bay area. Before you commit, you may want to charter up there for a week. The Hinckley fleet is, sadly, no more... but Buck's Harbor Marine (www.bucksharbor.com) runs a good
charter operation on the Eggomoggin Reach. That's a good stretch of water that has interesting places to go, fewer pots, and is pretty well protected. SSCA (ssca.org) also also has port captains that can answer specific questions about their local areas.
Hope this helps...Here's a typical boat you may see up there. Maine craftsmanship at its finest...mnh