Colchester Reef in Lake Champlain features the submerged stone-filled crib foundation of the original lighthouse. This site consists of three shoals known as the Middle Bunch, offering a range of depths from 2 to 40 metres. Access is by boat only, located 2414 metres from the shore. Divers and snorkellers should be prepared for variable conditions, including thermoclines and visibility ranging from 3 to 12 metres. Due to the depth and potential for cold water, this site is suited for advanced divers. Hazards include boat traffic, low visibility, and cold water temperatures that remain constant in the mid-40s Fahrenheit at greater depths.

The Cut is a 200-foot gap in the historic railroad causeway at Lake Champlain, serving as an artificial reef. The site features rocky crevices that provide habitat for various temperate freshwater fish and invertebrates. Divers and snorkellers can expect depths ranging from 2 to 6 metres, with an average of 4 metres. Access is via the shore, and the site is suitable for intermediate divers. Conditions include moderate currents, cold water, and potential boat traffic. The site is well-suited for night diving and offers a 4/5 rating for snorkelling. Typical dives last approximately 30 minutes. Facilities available at the site include parking and toilets.

Bruno's Reef is a rocky freshwater site located in Malletts Bay, Lake Champlain, situated between Coates Island and Marble Island. The reef features depths ranging from 6 to 11 metres. Access is by boat only, and the site is suited for advanced divers due to cold water conditions and variable visibility between 3 and 9 metres. A drysuit is recommended for this environment. While primarily a dive location, the shallower crests of the reef can be accessed by snorkelers. Species recorded around this area include snails, small mouth bass, and freshwater drum. Divers should remain aware of boat traffic in the area.

Rossetti Beach is a sandy freshwater site located on Lake Champlain near Colchester Reef. This sheltered cove provides easy shore access, making it suitable for beginner snorkelers. The site features a shallow, sandy bottom with depths ranging from 1 to 5 metres, averaging 3 metres. Conditions are generally mild, though divers and snorkelers should be prepared for cold water temperatures. Species recorded around this area include snails, small mouth bass, and freshwater drum. The site is also home to juvenile fish and various aquatic plant life. Typical snorkel sessions last approximately 45 minutes, and the site includes basic facilities such as parking and toilets.

Beer Can Island is a shallow, rocky island located near the mouth of Malletts Bay in Lake Champlain. The site reaches a maximum depth of approximately 5 metres. Access is by boat only, as the site is situated 8,000 metres from the shore. Snorkellers can expect visibility ranging from 3 to 9 metres. Due to the nature of Lake Champlain, the water remains cold, with temperatures typically ranging from the 40s to the mid-60s Fahrenheit in late summer. Drysuits are recommended for comfort. Hazards at this site include cold water and low visibility. This location is suitable for beginners.

Ausable Point State Park features a natural sand delta formed where the Ausable River enters Lake Champlain. This site offers a shallow, sandy shelf that extends into the lake, creating an accessible environment for snorkellers. Depths typically range from 1 to 5 metres, with an average of 2 metres. The area is suitable for beginners, though conditions vary. Divers and snorkellers should be aware of potential hazards, including cold water, boat traffic, and fluctuating visibility between 3 and 9 metres. Facilities at the park include parking, toilets, and showers. Access is via a shore entry, making it a straightforward location for those exploring the freshwater environment.

Butterfly Bay is a protected cove located on the western side of Valcour Island in Lake Champlain. The site features rocky limestone ledges and submerged boulders, offering visibility ranging from 10 to 30 metres. Divers and snorkellers should note that boat access is required to reach this location, situated 805 metres from the shore. Conditions include mild currents and sharp thermoclines, with bottom temperatures remaining in the mid-40s°F year-round. The habitat supports various temperate freshwater fish and invertebrates. Divers should remain aware of boat traffic in the area. Facilities including air fills, equipment rental, and boat charters are available nearby in Plattsburgh.

Lone Rock Point features the Champlain Thrust Fault, where 450-million-year-old rock formations meet the water. This shore-entry site consists of underwater boulders and crevices that create a complex reef-like topography. Depths typically range from 1 to 10 metres, with an average of 5 metres. Divers and snorkellers should be aware of variable conditions including cold water, thermoclines, surge, and surf. Due to the presence of boat traffic, appropriate surface markers are recommended. Species recorded around this area include snails, freshwater drum, small mouth bass, lake trout, and rock bass. Parking is available for visitors.