Stonington Point is a shore-entry dive site featuring a combination of natural reef and artificial reef structures. The site is suitable for beginners, with an average depth of 5 metres and a total range of 2 to 6 metres. Divers should be aware of moderate currents, surf, and potential hazards including boat traffic, entanglement, and sharp coral. Visibility at the site typically ranges between 2 and 9 metres. Water temperatures fluctuate significantly throughout the year, ranging from 5C in February to 21C in August. Night diving is permitted at this location, with typical dives lasting approximately 45 minutes. The habitat supports a variety of temperate marine life and invertebrates.

New London Ledge Lighthouse functions as an artificial reef located in the Long Island Sound. The site features a submerged foundation at depths ranging from 1 to 9 metres. Divers can expect visibility between 5 and 10 metres. Access is strictly by boat, and the site is suitable for beginners. Water temperatures fluctuate significantly, ranging from 5C in winter to 22C in summer, necessitating appropriate thermal protection. Moderate to strong currents are common, so divers should remain close to the structure. Guided tours are available and recommended to navigate the foundation safely and manage current conditions effectively.

Montauk Jettys in Long Island Sound provide a shallow shore dive ranging from 1 to 7 metres in depth. The jetty structure functions as an artificial reef, offering hard substrate for local marine life to colonise. Divers can expect mild currents and visibility between 3 and 6 metres. Due to the potential for surf, surge, and boat traffic, divers should exercise caution during entry and exit and use a surface marker buoy. This site is suitable for beginners and supports night diving. Parking is available on-site, though conditions vary, and divers should assess the shore break before entering the water.

Ocean Beach is a shore-entry snorkel site located in the Long Island Sound. The site features a reef area accessible directly from the beach. Water temperatures fluctuate significantly throughout the year, ranging from 5C in the winter months to 22C during the summer. Snorkellers should be aware of the physical hazards present at this location, including a surf and shore break at the entry point. Strong currents and rip currents are also common, requiring careful monitoring of local conditions before entering the water. Facilities available on site include parking, toilets, and a cafe for post-snorkel refreshments.

U-853 is a German Type IXC/40 submarine that rests upright on a sandy bottom at depths between 30 and 40 metres. Located 11 kilometres offshore, this wreck is largely intact and offers penetration opportunities for qualified divers. The site is subject to moderate currents and visibility ranging from 3 to 15 metres. Water temperatures fluctuate between 6 and 17 degrees Celsius, making a drysuit essential. Due to the significant depth, potential for nitrogen narcosis, and overhead environment, this site is strictly for advanced divers with wreck and deep certifications. Divers should monitor gas supplies and bottom time closely while navigating the structure.

Mashapaug Pond is a 300-acre freshwater lake located within Bigelow Hollow State Park in Union, Connecticut. Set inside the Nipmuk Forest, the site features rock formations and provides shore access for divers. Depths range from 4 to 12 metres, with an average depth of 5 metres. Conditions include mild currents and visibility between 2 and 10 metres. Water temperatures fluctuate significantly, ranging from 4.4°C at depth to 21°C at the surface during summer months. Divers should be aware of potential hazards including boat traffic, cold water, entanglement risks, and low visibility. Facilities available at the park include parking, toilets, showers, changing rooms, and a rinse station.

Horsehead is a marine site featuring a combination of reef and cave topography. Divers can explore depths ranging from 8 to 18 metres, with an average depth of 13 metres. The site is located 300 metres from shore and requires boat access. Conditions typically include mild currents and visibility between 5 and 10 metres. While the reef is accessible to beginners, the cave sections present an overhead environment. Divers without specific overhead training should remain within the natural light range of the exit and carry a dive torch. Due to potential surges and currents, check local conditions before planning your dive.

King's Beach offers a shore-entry dive across a combination of reef and seagrass habitats. The site is suitable for beginners, with depths ranging from 6 to 12 metres and an average depth of 8 metres. Divers should be aware of variable conditions, including mild currents, surge, and potential boat traffic. Visibility is limited, typically ranging between 0 and 6 metres. Water temperatures fluctuate significantly throughout the year, reaching a maximum of 18C during the summer months. Species recorded around this area include sea bass, wrasses, spotfin butterflyfish, barracuda, gurnard, angelfish, pufferfish, crabs, cornetfish, common sea stars, tailor, sea hares, righteye flounder, and various snails.