There is a privately maintained nun and can at the entrance to the inner harbor and the pier with the water. If you get water after hours, the shutoff valve is underneath the hut at the head of the pier. At least 6 ft of water all the way into the pier. There's a marine railway operated by Quisset Harbor Boatyard. If you're stuck for groceries, there's a Lil Peach store about a 40 minute walk towards Falmouth.
Dinghy dock to the left of the main pier.