You can make a quick jog into Wood's Hole and anchor at Hadley's Harbor which is beautiful, or go up to Onset which is just at the beginning of the Cape Cod Canal. Nothing to do at Hadley's but jump off and swim. Onset is not as pretty but there is a town.
Of course there is also Marion, Westport, Mattapoisett and other harbors, but the first two are my favorites.