Baie d'Ecalgrain near Cherbourg is a marine site featuring rocky reef topography and extensive kelp forests. The northern rocky point is a notable feature, characterised by deep gullies covered in kelp. This shore-entry site is suited for advanced divers due to the presence of surf and moderate to strong currents. Snorkelling is also popular, particularly during slack tide. Water temperatures fluctuate significantly throughout the year, ranging from 10C in the winter months to 18C in late summer. Facilities at the site include parking and toilets.

Port du Hable in Cherbourg, France, is a rocky reef site accessible from the shore. The topography is defined by large boulders and deep gullies that offer shelter for various marine life. Snorkellers can observe common species including sea hares, European green crabs, and snails. Less frequently encountered inhabitants include conger eels, spiny spider crabs, rock crabs, sea stars, brittle stars, sea squirts, and shannies. Water temperatures at this site fluctuate between 10C and 18C throughout the year. Due to the nature of the terrain, this site is best suited for intermediate-level snorkellers.

Landemer Cliffs near Cherbourg offers dramatic underwater topography defined by Green Siltite rock formations. This site features both reef and wall structures, reflecting the strong influence of the Atlantic. Snorkellers should be aware that this is an advanced site due to challenging conditions, including surf, rip currents, and strong currents. Water temperatures range from 10C in the winter to 18C in late summer. Access is via the shore, starting from the Sentier des Douaniers. Given the exposure to open water and variable currents, this location is best suited for experienced snorkellers comfortable with cold water and dynamic marine environments.

Port Racine, recognised as the smallest port in France, provides a sheltered shore entry into the rocky waters of the Hague. The site features a combination of natural reef and artificial structures, with kelp-covered rocks dominating the underwater topography. Conditions are generally mild, making this an accessible location for beginners. Species recorded around this area include conger eels, sea hares, various crab species such as spiny spider crabs and rock crabs, sea stars, snails, sea squirts, and shannies. Parking is available for visitors. Water temperatures fluctuate between 10C and 18C throughout the year, requiring appropriate thermal protection for snorkellers.

Fort de Chavagnac is an offshore 19th-century fort located 3000 metres from the shore near Cherbourg. The site features artificial rocky foundations that function as an artificial reef, attracting interest from divers and snorkellers. Diving depths range from 4 to 14 metres. Access to the site is by boat only, and guided tours are available. Conditions include moderate currents, though divers should be aware of the potential for strong currents in the area. Water temperatures fluctuate between 10C and 18C throughout the year. The site is suitable for intermediate divers and offers a 4/5 rating for snorkelling.

The Leopoldville is a technical wreck dive located off the coast of Cherbourg, France. Resting at depths between 38 and 65 metres, this site is reserved for advanced divers. Access is strictly by boat, and the site is characterised by strong, unpredictable currents. Divers must navigate an overhead environment with significant entanglement risks. Visibility typically ranges from 5 to 15 metres, and water temperatures remain cold, between 9 and 13 degrees Celsius. A drysuit is essential for this dive, and careful gas management is required due to the depth and conditions. Divers should plan their entry around slack water and consult with their charter skipper regarding current conditions.

Anse du Brick is a sheltered rocky cove located on the northern coast of the Cotentin Peninsula near Cherbourg. This site features shallow rocky reefs accessible directly from the shore, making it suitable for beginners. Depths start at 2 metres and vary across the reef. Water temperatures fluctuate between 10C and 18C throughout the year, requiring appropriate thermal protection. Divers and snorkellers should be aware of potential rip currents and the cold water conditions. Facilities at the site include parking and a cafe for visitor convenience.

Anse du Brick is a sheltered sandy cove located on the Cotentin Peninsula near Cherbourg. The site features rocky outcroppings on its flanks, providing a defined area for surface snorkeling. It is suitable for beginners, though conditions vary and users should be aware of potential surf and moderate currents. Facilities at the site include parking, toilets, showers, changing rooms, equipment rental, a cafe, and first aid services. Water temperatures range from 10C in the winter months to 18C in September.