Old Harry Sea Caves, located at the western edge of Grande Échouerie, feature dramatic red sandstone rock formations and crevices. This shore-entry snorkel site is best suited for intermediate snorkelers due to the potential for strong currents, surf, and rip currents. The site offers the warmest waters of the archipelago, though temperatures fluctuate significantly throughout the year. Snorkelers should be aware of entanglement hazards near the cliff structures. The habitat supports a variety of temperate marine life, including various fish and invertebrates typical of the region. Facilities at the site include parking, toilets, and showers.

Old Harry, located near Grande-Entree, offers a diverse underwater environment featuring a mix of sandy bottoms and rocky reef formations. Divers can explore small caves situated at the western end of the site, which share geological similarities with La Bluff. This site is suitable for intermediate divers due to the presence of strong currents and surf conditions. Entry is via the shore. Water temperatures fluctuate significantly throughout the year, ranging from -1C in winter to 18C in August. Divers should be aware of potential entanglement hazards and the challenging current. Facilities including toilets and showers are available for visitors.

Grande-Entrée Harbor Mouth, located near the fishing port of Grande-Entree, offers a combination of natural reef and artificial reef structures. This site is suited for advanced divers due to the presence of active boat traffic. Water temperatures fluctuate significantly throughout the year, ranging from -1C in winter to 18C in August. Divers and snorkellers can expect to encounter a variety of temperate marine life typical of the region, including various fish and invertebrates that inhabit these reef environments. Access to the site is available via both shore and boat entries. Snorkelling is possible here, though conditions vary based on the active maritime environment.

Bassin aux Huîtres is a shallow, calm bay situated between the main island and Île Boudreau. This site offers a sheltered environment away from open ocean waves, making it suitable for beginners. The topography consists of reef and seagrass habitats, which support a variety of temperate marine life and invertebrates typical of the region. Access is via the shore, and conditions are generally characterised by mild currents. Water temperatures fluctuate significantly throughout the year, ranging from -1C in late winter to 18C in August. Snorkellers should be prepared for these variable conditions when planning their visit to this coastal location.

La Bluff in Cap-aux-Meules offers a distinct snorkeling experience defined by dramatic red sandstone cliffs and accessible sea caves. Snorkelers can navigate through narrow passages and chambers carved into the rock by the Gulf of St. Lawrence. The site features both cave and reef topography, requiring intermediate skill due to the presence of overhead environments, surf, and surge. Water temperatures fluctuate significantly throughout the year, ranging from -1C in winter to 18C in August. Guided tours are available through local dive shops to assist with shore entries. The habitat supports a variety of temperate marine life, including various fish and invertebrates typical of the region.

Boudreau Island Peninsula near Cap-aux-Meules offers diverse snorkeling environments across its coastal geography. The Bassin aux Huîtres side provides shallow, calmer, and warmer conditions, while the seaward side features rugged cliffs and deeper water for exploration. This site consists of both natural reef and artificial reef structures. Access is via shore entry. Snorkelers should be prepared for moderate currents and potential surf. Due to the presence of sharp coral and strong currents, this site is recommended for intermediate snorkelers. Water temperatures fluctuate significantly throughout the year, ranging from -1C in winter months to 18C in August.

East Cape in Cap-aux-Meules offers a diverse underwater environment featuring a mix of natural reef and artificial reef structures. The site transitions between lagoon-like conditions and open-sea exposure, resulting in variable underwater environments. Divers should be prepared for depths ranging from 2 to 15 metres, with an average depth of 8 metres. Access is via a shore entry, though conditions can be challenging due to strong currents and surf. Given these factors, the site is best suited for intermediate divers. Facilities available at the location include parking, toilets, and showers. Water temperatures fluctuate significantly throughout the year, ranging from -1°C to 14°C.

Rockhill Point in Cap-aux-Meules offers a unique transition from wooded hillsides directly into the marine environment. This reef site features a rocky shoreline that provides shelter for smaller crustaceans and juvenile fish. Snorkellers can access the site directly from the shore. Conditions at this location vary, with water temperatures ranging from -1C to 18C throughout the year. Divers and snorkellers should be aware of potential hazards, including cold water, low visibility, and strong currents. Due to these environmental factors, the site is best suited for those prepared for cold-water conditions.