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.

Eastcliffe Hall is a freshwater shipwreck located 1200 metres offshore in the Brockville and Thousand Islands region. The wreck lies at depths between 6 and 30 metres, with an average depth of 18 metres. Divers must access the site by boat. Conditions include strong currents and visibility ranging from 5 to 10 metres. The wreck presents an overhead environment with potential entanglement hazards, requiring intermediate skill levels and proper equipment. Water temperatures remain consistent from the surface to the bottom during summer months. Guided tours and boat charters are available for those exploring the hull, and night diving is permitted.

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.

The Conestoga Wreck is a shore-accessible artificial reef located 23 metres from the Brockville Waterfront. Resting at depths between 3 and 9 metres, this site is suitable for beginners. Divers experience a moderate current, which introduces a drift element to the 40-minute dive. Visibility is variable, ranging from 3 to 25 metres. The site lacks a thermocline and maintains warmer temperatures than many other regional freshwater locations. Night diving is permitted, offering a different perspective of the structure. Hazards include entanglement risks and currents that can strengthen unexpectedly. Divers should secure loose equipment and maintain buoyancy control. Parking is available at the site.

Torpedo Run is a navigational dive that begins at the Wee Hawk site, proceeds through the canal into the Saint Lawrence, and passes the Conestoga wreck. The route concludes at the beach near the legion. Divers should be aware that this site is subject to strong currents and variable visibility ranging from 1 to 6 metres. Due to the current, this site requires careful planning and navigation. It is accessible via both shore and boat entries. Water temperatures fluctuate between 25C and 30C throughout the year. This site is suitable for beginners, though the current conditions necessitate appropriate experience in moving water.

Weehawk is a shallow drift dive and snorkel site located in the St. Lawrence River near Brockville. The site features the remains of an old steel ferry and the historic Lock 27. Divers and snorkellers can explore these structures at depths ranging from 3 to 6 metres, with an average depth of 4 metres. The site is accessed from the shore and is subject to strong currents, making it suitable for intermediate divers. Visibility varies between 5 and 18 metres. Due to the nature of the site, divers should be aware of potential boat traffic and entanglement hazards.

Lock 27 is a freshwater wreck dive located 800 metres from shore in the St. Lawrence River. The site sits at depths between 4 and 8 metres, with an average of 6 metres, making it suitable for intermediate divers. Divers experience a moderate current that can increase unexpectedly, requiring careful planning with a boat operator. Visibility typically ranges from 3 to 6 metres, and the use of a dive torch is recommended. Due to the wreck structure, entanglement hazards exist, and carrying a cutting tool is advised. The site is accessible by boat and supports night diving. Divers should be prepared for cold water temperatures.

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.