The Waterford Boat Launch on Dock Road in Waterford is one of a very few places you can dive from shore in Connecticut. In the summer, it can be difficult at times to dive here during the day because of boat traffic and hoards of fisherman on rocks. This is especially true on holiday weekend and in the summer time however the launch typically clears out as the sun sets and it can make for a decent night dive. In the winter this area is basically a ghost town so you won't have any problems getting in and out of the water, just be careful if there is snow and ice on the boat launch and parking lot.
Technically you aren't supposed to dive from the launch but as long as you are courteous and don't block the boats coming in or leaving the launch you won't run into too many issues. If the launch just has too many boats to make for a safe dive, you can go a little further south on New Shore Rd. to the Pleasure Beach parking lot on the left side of the road. There is public access to Pleasure Beach a few houses down on the right but be prepared to walk a bit. See the CT DEEP website for more info.
When you enter the parking there is parking to the left and on the right near the launch. There is also a private parking lot for the Pleasure Beach Waterford Association which you cannot use unless you're re a member. Access to the beach from the parking lot is also not typically allowed by the association, if someone is there watching the parking lot they will refuse access and you will either have to use the launch or the public access.
The maximum depth you will see at the site is 18-20 feet but if you dive the rock line near the shore you will probably be in the 10-15 ft. range. If you're able to enter by walking down the boat launch be careful because it can get slippery near the water. There is also a small drop as ou walk off the launch and once you are in you can put your fins on quite easily. Try not to stay in front of the launch for too long as boats will be going in and out and you don't want to risk getting run over. As soon as your fins are on, swim around the rocks clear of the launch and descend. If you have never been SCUBA diving here before a nice way to dive the site is to follow the rocks down to where they meet the sand and follow the rock line all the way around to the beach. If you're night diving you can poke around in all the cracks and crevices of the man-made stone blocks and the rocks to catch lobster. If you do catch lobster be sure you have a license and measuring gauge as the DEEP warden does pop in to check that you do.