Cale de Jouvente in Saint-Malo offers a rocky drop-off reaching depths of 16 metres. This shore-entry site is suitable for intermediate divers, though conditions vary due to currents and boat traffic. Access is strictly governed by tidal windows influenced by the nearby tidal power plant, requiring careful planning. Due to these specific tidal constraints and local conditions, supervision by a qualified instructor is mandatory for first-time visitors. The site is accessible at both high and low tide, provided the strict operational windows are observed.

Le Bizeux is a marine dive site located in Saint-Malo, France, offering depths between 8 and 20 metres. The topography features a drop from approximately 10 metres at the anchor point down to 20 metres. Divers can access the site by boat or from the shore, though moderate currents and visibility ranging from 1 to 10 metres require advanced skill levels. Marine life recorded at this site includes European Common Cuttlefish, Mantis Shrimp, Catshark, Squat Lobster, Common Lobster, various crabs including Spiny Spider Crab and Rock Crab, Bream, Shrimp, Spirograph, Abalone, Striped Red Mullet, and the Grey Sea Slug.

Csce is a reef and wreck site located off the coast of Saint-Malo, France. Accessible only by boat, the site features depths ranging from 5 to 20 metres with an average of 12 metres. Divers encounter moderate currents and should be prepared for potential hazards including entanglement, low visibility, and surf. Marine life recorded here includes common spiny spider crabs and shrimp, alongside less frequent sightings of European common cuttlefish, squat lobsters, common lobsters, catsharks, wrasses, mantis shrimp, flatworms, conger eels, sea slugs, spirographs, pipefish, and abalone. Water temperatures vary from 9C to 15C, necessitating a 7mm wetsuit in summer and a waterproof suit with gloves and booties during spring and autumn.

Plage du Môle is a sheltered city beach situated directly beneath the ramparts of Saint-Malo. This site features a combination of natural reef and artificial reef structures, specifically around the Roches Noires near the jetty. It is suitable for beginners, offering shallow depths ranging from 1 to 3 metres with an average of 2 metres. Access is via the shore. Conditions vary, with visibility typically between 1 and 8 metres and water temperatures fluctuating from 9C in February to 19C in August and September. Divers and snorkellers should be aware of potential hazards including low visibility and moderate to strong currents.

Sprungturm is a marine dive site located in Saint-Malo, France, featuring a reef and drop-off topography. Divers can expect depths ranging from 12 to 15 metres, with an average depth of 13 metres. Access to the site is via the shore. Conditions at this location are variable, with visibility typically ranging between 5 and 15 metres and strong currents present. Facilities available at the site include changing rooms and showers. Due to the current and environmental conditions, this site is suited for intermediate divers.

Grand Bé is a tidal island located off the coast of Saint-Malo, France. Accessible on foot at low tide, the site offers shore-based snorkeling opportunities. The most suitable areas for snorkeling are found along the western and northern rocky edges of the island, where the incoming tide circulates water. Conditions at this site vary, with water temperatures ranging from 9C in February to 19C in August and September. This location is suitable for beginners, though snorkelers should be mindful of the tidal nature of the island when planning their visit.

Petit Bé is a reef site located 400 metres from the shore near Saint-Malo. This site features deep gullies between rocks and is suitable for intermediate snorkellers. Depths range from 2 to 10 metres, with an average of 6 metres. Conditions are variable, with visibility between 3 and 10 metres and strong currents present. Water temperatures fluctuate throughout the year, ranging from 9C in February to 19C in August and September. Access is via the shore, and the site offers nearby facilities including parking, toilets, showers, and a dive shop. Typical snorkelling sessions last approximately 45 minutes.

Located 3500 metres from the coast of Saint-Malo, the South Beach of Île de Cézembre is a reef site accessible only by boat. The area features rocky outcroppings and shallow waters ranging from 2 to 8 metres, with an average depth of 5 metres. This site is suitable for beginners and offers a snorkel rating of 4 out of 5. Divers and snorkellers should be aware of moderate currents and boat traffic in the vicinity. Water temperatures fluctuate between 9C in February and 18C in August and September. Facilities on the island include a cafe and toilets.