3 curated Scuba Diving spots in Mauritius, each with its own note and source.
Grand Port · Best time: Oct–Apr · Beginner
A marine park since 1997: the coral gardens in zone 1 stay at a steady 5 to 6 metres, the eastern lagoon at 2 to 3 metres — snorkelling water, not depth diving. Zones 1 and 2 are boat-access only; zones 3 and 4 are free from shore. Butterflyfish, parrotfish and surgeonfish are regular, turtles occasional.
Sources: Snorkeling Report
Black River · Best time: Oct–Apr · All levels
The Cathedral off Flic en Flac is a system of caves, arches and swimthroughs between 18 and 28 metres — an overhead environment, so Advanced Open Water and experience are required. Visibility on the west coast is often 20 to 30 metres with light current; May to November are the calmest months. Moray eels, lionfish and grouper sit in the rock.
Sources: DivingMauritius.mu
Pamplemousses · Best time: Oct–Apr · All levels
Off Trou aux Biches lies the Stella Maru, a roughly 50-metre Japanese freighter scuttled in 1987 and now at 18 to 25 metres — rated intermediate, with Open Water divers staying outside alongside a guide. Visibility around 25 metres, current mostly mild, calmest months May to November. Penetration needs a primary light plus a backup.
Sources: DivingMauritius.mu, Beachcomber Tours, Supconnect
Without a dedicated Scuba Diving note yet, listed on the country page: Île aux Cerfs.