Port Union in the Niagara Peninsula features extensive stone breakwaters that function as artificial reefs. These structures, composed of large armour stone, provide complex topography for exploration. The site is accessed from the shore and is suitable for intermediate snorkelers. Depths range from 2 to 6 metres, with an average of 3 metres. Conditions include mild currents and visibility typically between 4 and 5 metres. Hazards at this freshwater location include cold water, surf, and surge. Facilities at the park include parking and toilets. Snorkelers should be prepared for variable water temperatures, which fluctuate from 4C in winter to 22C in August.

Rouge Beach is located where the Rouge River meets Lake Ontario, providing a transition between marsh and lake environments. Snorkelers can explore the sandy channel and the edge of the marsh vegetation. This site is suitable for beginners and offers shore access. Water temperatures fluctuate significantly throughout the year, ranging from 4C in winter to 22C in August. Divers and snorkelers should be aware of moderate currents and potential rip currents. Cold water temperatures during spring and autumn pose a risk of hypothermia, particularly in April when temperatures average 3.7C. Parking and toilets are available at the site.

Guild Park offers a unique freshwater snorkelling experience along a rocky shoreline. The site features an artificial reef created by historical erosion control efforts, consisting of large concrete slabs and stone debris scattered underwater. Access is via a trail at the end of Galloway Road, requiring a shore entry. Due to the nature of the submerged structures, this site is suited for advanced snorkellers. Water temperatures fluctuate significantly throughout the year, ranging from 4C in winter to 22C in August. Divers and snorkellers should be aware of potential hazards including entanglement and sharp debris. Parking is available for visitors.

Petticoat Creek offers a rugged snorkeling experience situated below scenic bluffs. The shoreline is characterised by rocky terrain, providing structure and crevices that differ from nearby sandy beaches. This site is suitable for intermediate snorkelers and requires a shore entry. Conditions vary, with visibility typically ranging between 3 and 6 metres and water temperatures fluctuating from 4C to 22C throughout the year. Be aware of potential hazards including boat traffic, surf, and cold water. Species recorded around this area include Alewife, Common Carp, Blue Gill, Sun Perch, Common Perch, Trout, Round Goby, Brown Bullhead, American Crayfish, Pike, White Sucker, and Small Mouth Bass.

Rotary Frenchman's Bay West Park, located on the southwest shore of Frenchman's Bay, provides a sheltered freshwater environment suitable for beginner snorkellers. The site features a sandy, shallow entry point leading to depths ranging from 1 to 5 metres, with an average depth of 3 metres. Conditions are generally mild, though water temperatures fluctuate significantly throughout the year, ranging from 4C to 21C. The area is well-supported by facilities including parking, toilets, showers, changing rooms, and a rinse station. Visitors can also access a nearby cafe, dive shop, and guided tour services. Typical snorkelling sessions last approximately 45 minutes.

Beachfront Park in Pickering provides a shore entry into the freshwater environment of Lake Ontario. The site features a mix of sandy and rocky bottom topography that can shift following storm activity. Suitable for beginners, this location offers mild currents, though conditions vary significantly. Water temperatures are cold, fluctuating between 4C and 21C throughout the year. Snorkellers and divers should remain cautious of hazards including cold water, low visibility, surf, and rip currents. The park is well-equipped with amenities such as parking, toilets, showers, changing rooms, a rinse station, and an on-site cafe, with a dive shop located nearby for equipment and support.

The Alexandria is a shallow wreck located in the Niagara Peninsula, resting at a consistent depth of 7 metres. This freshwater site is accessed via a shore entry, which requires caution due to potential surf and swell. Divers should be prepared for variable conditions, with visibility ranging from 3 to 15 metres and water temperatures fluctuating between 4 and 20 degrees Celsius. A drysuit or well-sealed wetsuit is recommended for most of the year. The site features a mild current, though divers must remain aware of entanglement risks around the wreck structure and active boat traffic in the area.

Alex Robertson Park offers a quiet shoreline entry point at the eastern end of the Pickering waterfront. Located near the Hydro Marsh barrier, the site features shallow water where visibility is often variable due to marsh runoff. This freshwater location is suitable for beginners, though conditions are subject to cold water, potential entanglement, and surf. Water temperatures fluctuate significantly throughout the year, ranging from 4C in winter to 21C in August. Species recorded around this area include Round Goby, Brown Bullhead, snails, Alewife, Common Carp, Small Mouth Bass, White Sucker, Pike, Trout, Sun Perch, American Crayfish, Blue Gill, Rainbow Trout, and Common Perch. Facilities at the park include parking and toilets.