Mayotte
One of the largest lagoons in the world, enclosed by a double barrier reef around Mayotte, with drift dives in reef passes such as the Passe en S, turtles, rays, dolphins and humpback whales.
Mayotte is surrounded by one of the largest enclosed lagoons in the world. An outer barrier reef of more than 179 km lies 3 to 15 km offshore, and in the southwest a second, inner barrier makes it a rare double barrier reef. The barrier is broken by about a dozen passes 12 to 70 m deep, which are the main dive sites. The best known is the Passe en S (Longogori Pass) in the east, a 2 km winding channel and nature reserve with turtles, groupers, napoleon wrasse, rays and occasional sharks. In the south, Passe Bateau, Boueni and Sada offer drift dives and deep drop-offs, while N'Gouja is a shore dive with green turtles. Since 2010 all of Mayotte's waters form the Mayotte Marine Natural Park, recording about 760 fish species and 24 marine mammals. Dive centres are based in the east around Mamoudzou and Petite-Terre and in the south. Source: Wikipedia, Lagon Maoré, Petit Futé