Lake Champlain is the winner by a long shot. Learn more here in my thread:
Primer to Diving Lake Champlain
Base yourself in Burlington. For accommodation, you have numerous Airbnbs, hotels, etc. You can even camp near the beach. Waterfront Diving Center in Burlington runs 2-tank charters most weekends from June-Oct. Great shop. There are places to shore dive from as well. Plus after your dives, plenty of restaurants, shops, trails, etc.
Otherwise:
The runner-up would be Lake Winnipesaukee, which is closer to Boston, has wrecks, accommodation and boat charters. Shore diving is doable.
Lake Willoughby has deep dives with interesting rocks, accommodation, no charters. Just as far as Burlington though.
Lake Sunapee is the closest of these to Boston, has one wreck, accommodation, no boat charters.