Big Hill Sea Caves on Entry Island features towering red sandstone cliffs and deep sea caves accessible by boat. This reef site is suited for advanced divers due to hazards including overhead environments, surf, surge, and moderate currents. The site reaches depths of 1 to 10 metres, with an average of 5 metres. Visibility ranges from 3 to 10 metres. Water temperatures are cold, fluctuating between -1°C and 18°C throughout the year. The base of the cliffs provides a dynamic environment for snorkelling, though boat access is required to reach the site located 500 metres from shore.

Entry Island Cliffs feature dramatic wall and reef topography located 12 kilometres from shore. This remote site is accessible by boat from Cap-aux-Meules. Snorkellers should be prepared for challenging conditions, as the area is subject to strong currents, rip currents, and surf. Water temperatures are cold, ranging from -1°C in winter to 19°C in August. Due to these environmental factors and the exposed nature of the cliffs, this site is recommended for advanced snorkellers only. Toilets are available for visitor use. The site is noted for its high cliffs and clear water conditions within the archipelago.

La Cormorandière Islet is a rocky reef located off the northeast tip of Entry Island. The underwater topography is defined by rugged terrain, featuring large boulders and deep crevices. This site is suitable for advanced snorkellers due to the presence of strong currents and surf. Access is exclusively by boat, with typical sessions lasting around 45 minutes. Water temperatures fluctuate significantly throughout the year, ranging from -1C in late winter to 19C in August. Facilities including a cafe and toilets are available on Entry Island. As a marine environment, the site supports a variety of general marine life and invertebrates within its rocky habitat.

Plage du Port on Entry Island provides a sheltered shore entry point located just south of the main ferry pier. The site features a mix of sandy and rocky bottom topography, making it a practical location for beginners to practise snorkelling. Water temperatures are cold throughout the year, ranging from -1°C in winter to a summer peak of 19°C in August. Visitors should expect brisk conditions, with summer averages typically between 10°C and 18°C. On-site facilities include toilets and a cafe, providing convenient support for those accessing the water from the shore.

Les Demoiselles is a wall dive site located at Entry Island, featuring the underwater extension of red clay and gypsum cliffs. The site is suitable for intermediate divers due to the presence of strong currents and potential surf conditions. Access is available via both shore and boat entries. Water temperatures fluctuate significantly throughout the year, ranging from -1C in late winter to 19C in August. Parking facilities are available for visitors. While the site offers opportunities for both diving and snorkelling, users should be prepared for the challenging current conditions characteristic of this location.

Cap Alright is situated below the lighthouse in Cap-aux-Meules, Canada. The site is defined by its grey cliffs and a rocky seabed. Due to the nature of the local waters, which are considered dangerous, this location is suitable only for advanced snorkellers. Snorkelling should be attempted exclusively on extremely calm days. Water temperatures at this site fluctuate significantly throughout the year, ranging from a low of -1C in February and March to a high of 19C in August. Access to the water is via the shore.

Pointe-Basse Harbour Rocks in Cap-aux-Meules offers a rugged shore entry near a traditional fishing wharf. The site features a combination of natural rock formations and a breakwater, creating a distinct underwater environment. Divers should expect moderate currents and be aware of boat traffic and surf conditions. Water temperatures are cool, ranging from -1C to 19C throughout the year, with August typically being the warmest month. The site is suitable for intermediate divers, and parking is available for convenience. Snorkelling is also possible at this location, which provides a view of the local cold-water ecosystem.

Parc de Gros-Cap, located on Cap-aux-Meules, offers a distinct coastal environment defined by dramatic red sandstone cliffs and accessible sea caves. The site features a combination of reef and cave topography, with shallow waters suitable for exploring underwater tunnels and rock formations. Access is via the shore, making it a convenient location for beginners. Divers and snorkellers should be aware of moderate currents and potential surf conditions. Water temperatures vary significantly throughout the year, ranging from -1°C in winter to 19°C in August, with warmer conditions occasionally found in local lagoons and bays during late summer.