Welcome to cold-er water diving, Dr. Steve! And yes, Hartford is not really near anything. But there is some diving in the state, you just have to decide if it's for you. Fresh water diving: There are multiple lakes in CT, and the Connecticut River is right there (I know people have dove it in CT, and in parts of the river that are in MA). Too bad you don't like quarry diving, as in nearby Portland, and major dive local is in the process of being constructed out of an old quarry (using Dutch Springs in PA as a template).
Salt Water: A bit tougher, but you can take a ride up to Mass/Boston (1.5 hours) for shore/boat diving. Very dedicated community of divers up there, and lots to see underwater. RI (also about 1.5 hours) diving is also not too bad; good shore dives, and you can ferry over to Block Island and dive the U-Boat. For a thrill, you can go out on one of of the shark charters and go cage diving (or not) with Makos and Blue Sharks. CT is not good for salt water diving, except maybe to lobster/hunt or just to get wet.