We are "from away" but are local Five Islands "summer people" in Georgetown since we bought our cottage in 1999 (Mussel Cove mentioned by momofboys_10). Small and a little remote is a good description, but we have never felt bored or removed while staying here, just relaxed in a way we can't achieve at home (we have no TV here nor high speed wireless).
It's really all about the sea in Georgetown, and we are blessed with Reid State Park (which could easily consume a full week if you really explore the place and don't just sit at the beach or lagoon). We purchase a pass at the beginning of the season and use it for ourselves and leave it for our guests.
There are tidepools to explore. Mackeral to jig for at the town wharf. Clams to dig at Reid. Swimming at Charles' pond. Trails to hike at Reid, Ledgemere, and the Josephine Neuman sanctuary. Seafood and ice cream to consume. Five Island farms market local veggies and artisan cheeses to try. 5 star dining at Robinhood Meetinghouse or in the rough lobster at Sarah's dockside or the 5 Islands Wharf. Old fashioned parades, boat blessings, laughing gulls, osprey, seals, wild turkeys, and maybe even a moose.
Rent a kayak and explore Macmahan Island and the Islands of the 5 Islands (or stay at a place like ours that has a kayak). Pick up a good book at a store in Bath or at the sometimes open little library. Check out the Maine Maritime Museum and antique shops in Bath. Take an excursion to famous LL Bean or to Rockland to the Farnsworth Museum. Drive into Portland and catch baseball the way it used to be (Sea Dogs) - it's only 45 min and $40 for a family of 4.
Do a puzzle. Read a book. Make new friends. Or...just sit on the rocker on the dock and watch the tide come and go.