Scuba Diving — Passe en S

Scuba diving at the Passe en S is one of the signature underwater experiences of Mayotte, the French overseas department in the Comoros archipelago of the western Indian Ocean. The Passe en S is a narrow S-shaped gap in the barrier reef of the southern lagoon, reached by a boat transfer of roughly 20 minutes from Kani-Keli on the southwest coast of Grande-Terre. Tidal water flows through the passage, which draws pelagic fish, rays, reef sharks and large schools of reef fish, while the walls of the channel are covered in healthy hard and soft corals. Mayotte hosts one of the largest enclosed lagoons in the world, and dives here are usually relaxed drift or wall dives with good protection from ocean swell. The activity is a certified-diver outing, so visitors normally need an open-water certification or equivalent. Beginners can ask the dive centre about a supervised introductory dive in calmer sites of the lagoon rather than in the passage itself, where current can be noticeable. Basic fitness, comfort in the water and the ability to equalise are expected; divers with ear, sinus, heart or respiratory conditions need medical clearance, and a minimum age of about 8 to 10 applies for junior programmes. The operator listed for the area, Plongée Mayotte, supplies the buoyancy control device, regulator, wetsuit and tank, while divers bring swimwear, a towel and reef-safe sunscreen. Operators in French territory work under French diving standards, with a pre-dive safety briefing, buddy checks, an oxygen kit on board and an emergency plan that relies on the boat radio and evacuation to the hospital in Mamoudzou. Visibility is best from April to November, typically 15 to 30 metres, while the rainy season from December to March brings more run-off and rougher seas. A single dive costs about €45 to €60 and a five-dive package about €190 to €240. Sessions last two to four hours including the boat transfer and briefing.