Pierre Noire is a reef site located off the coast of Saint-Malo, France. This site is suited for intermediate divers and requires boat access. The topography consists of a reef structure with an average depth of 10 metres. Divers should be aware of moderate currents and potential hazards including entanglement and sharp surfaces. Water temperatures at this location range from 11C in the winter months to 16C in August. Night diving is permitted at this site. Due to the nature of the environment, divers should maintain good buoyancy control to navigate the reef safely.

Île Verte is an uninhabited islet located 1852 metres from the shore near Saint-Malo. The site features a combination of reef and seagrass habitats, with a shallow lagoon area between the rocks. Diving and snorkelling are conducted via boat access. Conditions at the site are variable, with depths ranging from 5 to 15 metres and visibility between 3 and 10 metres. Divers and snorkellers should be aware of moderate currents and potential low visibility. The site is suitable for beginners, with typical dives lasting approximately 45 minutes. Water temperatures remain cool throughout the year, fluctuating between 11C and 15C.

Île Louët is a distinctive rocky islet in the Baie de Morlaix, recognisable by its lighthouse and cottage. The southern cove provides a sheltered environment for snorkelling, characterised by shallow waters and a dense kelp ecosystem. Due to the nature of the site and local conditions, this location is suited for advanced snorkellers. Access is possible from both the shore and by boat. Water temperatures fluctuate throughout the year, ranging from 11C in the winter months to 17C in August. Divers and snorkellers should be prepared for variable conditions typical of this coastal region.

Le Corbeau is a reef dive site located in the Baie de Morlaix, Saint-Malo, offering depths between 15 and 30 metres. Divers access the site by boat to explore the reef structure. Visibility varies significantly, ranging from 10 to 30 metres. The site is subject to strong currents, making it essential to time dives around slack water and use a surface marker buoy. Water temperatures remain cool throughout the year, between 11 and 14 degrees Celsius, necessitating a thick wetsuit or drysuit. While suitable for beginners, the conditions require careful planning. Species recorded around this area include gray seals, squat lobsters, wrasses, common lobsters, catsharks, conger eels, flatworms, crabs, sea hares, sea stars, shrimp, spiny spider crabs, soft corals, and brittle stars.

La Base à Dom is a marine dive site located in Saint-Malo, France. The site features a consistent depth of approximately 10 metres. Water temperatures in this area fluctuate throughout the year, ranging from 11C in the winter months to 16C during August. Given the depth and environmental conditions, this site is suitable for divers with appropriate cold-water experience. Access to the site is typically managed via boat from the local area. As a marine environment, the topography is subject to the tidal conditions characteristic of the Brittany and Normandy region.

Plage de Tahiti in Saint-Malo offers shore-access snorkeling along the rocky fringes of the Pointe de Pen al Lann. The site features a combination of seagrass beds and boulder formations, providing a varied environment for snorkelers. Conditions are suitable for beginners, though the area is subject to surf and mild to strong currents. Water temperatures remain cool throughout the year, ranging from 11C to 17C, making wetsuits recommended for comfort. Species recorded around this area include various crabs, wrasses, sea stars, and soft corals. Parking is available nearby for easy access to the beach.

Île Noire is a dark, rocky reef located near the Château du Taureau in the Baie de Morlaix. This site offers depths ranging from 0 to 21 metres and requires boat access. Divers and snorkellers should be prepared for moderate currents and water temperatures between 11C and 14C, which remain cool throughout the year. Species recorded around this area include crabs, wrasses, squat lobsters, conger eels, flatworms, common lobsters, catsharks, spiny spider crabs, shrimp, sea stars, sea hares, soft corals, abalone, and gray seals. Due to the conditions and depth, this site is suited for advanced divers.

Located at the northern tip of Île Callot near the Baie de Morlaix, this site features rugged granite topography characterised by deep crevices. Accessible from the shore, the area is reached via a submersible road at low tide. Divers and snorkellers can explore depths ranging from 4 to 20 metres, with an average depth of 12 metres. Conditions vary, with visibility typically between 3 and 10 metres and moderate currents. Due to the presence of rip currents, strong currents, and surf, this site is suited for intermediate skill levels. Parking is available for visitors. Typical sessions last 45 minutes, with water temperatures fluctuating between 11C and 17C throughout the year.