Crysler Park Beach in the United States near Morrisburg is a designated swimming area suitable for beginner snorkelers. The site features a sandy bottom and depths ranging from 1 to 5 metres, with an average depth of 3 metres. Snorkellers can expect mild currents and visibility typically between 3 and 8 metres. Access is via a shore entry, and the site is equipped with parking, toilets, showers, changing rooms, and a cafe. Hazards at this location include boat traffic, cold water, and low visibility. A typical snorkel session lasts approximately 30 minutes.

Lock 23 offers a unique freshwater experience featuring the submerged remains of a historic lock and sections of the old Morrisburg waterfront. Located in the United States, this site is suitable for beginners, with depths ranging from 0 to 4 metres and an average depth of 3 metres. Divers and snorkellers can access the site easily from the public beach. Conditions vary, with visibility ranging from 3 to 24 metres and mild currents present. Facilities at the site include parking, toilets, changing rooms, and showers. Typical dives last approximately 45 minutes. Hazards include cold water, low visibility, and strong current.

The Hydroelectric Plant is a freshwater dive site located at the end of Augusta Street in Morrisburg, United States. This artificial reef consists of the submerged foundations of an early 1900s power plant, featuring concrete structures and a berm. Divers can explore architectural debris across depths ranging from 10 to 35 metres, with an average depth of 30 metres. Access is via the shore, and the site is suited for intermediate divers due to moderate currents and potential hazards including entanglement and low visibility. Visibility can reach up to 60 metres. Toilets are available at the site. Typical dives last approximately 30 minutes.

The Lost Villages is a unique freshwater site where remnants of the original Highway 2 remain submerged in the St. Lawrence River. Divers can follow asphalt roads, yellow lines, and road signs that lead into the depths. The site is suited for intermediate divers due to moderate currents and potential entanglement hazards. Visibility is variable, ranging from 20 to 80 metres. The water temperature remains consistent throughout the depth profile with almost no thermoclines. Facilities at the site include parking, toilets, showers, changing rooms, a rinse station, air fills, a dive shop, and boat charter services. Snorkelling is possible but limited, with a rating of 2 out of 5.

Lock 21 is a submerged 19th-century Victorian lock located in the Brockville and Thousand Islands region of Canada. This site features massive stone walls and upper structures that remain visible just below the surface. Divers access the site from the shore, with the structure situated approximately 30 metres out. The depth ranges from 9 to 18 metres, with an average of 14 metres. Conditions include strong currents, low visibility of 3 metres, and cold water, making this an advanced dive. Facilities at the site include toilets and showers. Snorkellers can explore the upper structures near the surface.

Mille Roches Beach is the largest sand beach on the St. Lawrence River, providing a gentle shore entry for snorkelers. The site features a shallow bay with depths ranging from 1 to 5 metres, averaging 3 metres. Conditions are generally mild, though visibility varies between 1 and 3 metres. The area is suitable for beginners interested in observing local aquatic plants and the general kinds of temperate freshwater fish and invertebrates expected in this habitat. On-site facilities include parking, toilets, changing rooms, showers, and equipment rental.

Power House is a wreck and artificial reef located in the Great Lakes region of Ontario. The site sits at depths ranging from 16 to 29 metres, with an average depth of 19 metres. Divers encounter moderate currents that can strengthen unpredictably around the structure, requiring careful planning to work into the current during the outward leg. Visibility typically ranges between 5 and 10 metres, necessitating close-quarters navigation. Due to the cold water and overhead environment, this site is suited for intermediate divers with solid buoyancy control. Boat access is required to reach the site, which is situated 1000 metres from shore. Night diving is permitted at this location.

Cattle Culvert is a shallow artificial reef located near Guindon Park in the Brockville and Thousand Islands region. This site features a stone-cut railroad culvert, historically used for cattle crossings, which now rests underwater. Accessible via a shore entry from Lakeview Beach, the site is suitable for beginners. Divers and snorkellers can explore the structure at depths ranging from 1 to 10 metres, with an average depth of 5 metres. Conditions are generally mild with visibility varying between 3 and 10 metres. Divers should be aware of potential entanglement hazards due to the nature of the submerged structure. Facilities including parking, toilets, and showers are available nearby.