Nosy Be

Boats leave straight off the sand. The dive centres cluster along the south-west beaches around Ambatoloaka, tenders go out through the shallows at whatever the tide allows, and the day is shaped by how far you intend to go. The reefs off Nosy Tanikely and Nosy Sakatia are a short run and get dived as an unhurried two-tank morning. The Mitsio Archipelago sits far enough north that reaching it means a full day at sea, or a leg on a small safari boat with bunks aboard.

The geology is volcanic and it shows. Inshore, the islets are ringed by shallow coral slopes on sand, and the water often carries a green cast from plankton and mainland runoff rather than the blue of an atoll — good for life, harder for wide-angle photography. Further out, the Mitsio islands stand as bare basalt above the waterline and continue below as pinnacles and columns dropping into open water. They are exposed, so those trips are weather-dependent, and the pay-off is depth and blue rather than coral.

The whale shark season is a surface activity rather than a dive: boats look for animals feeding near the top of the water and people get in with mask and fins, so it sits alongside the scuba day rather than inside it. Humpbacks are watched from the boat. The place suits divers relaxed about organisation who want the country as well as the water — little here is polished, most operators close through January and February, and March is a rebuilding month rather than a full season.