Diégo-Suarez / DIANA

The DIANA region occupies the northern tip of Madagascar, a dramatically dissected landscape of headlands, deep bays and offshore islands where the Mozambique Channel narrows before opening again toward the Comoros. The centrepiece is the Baie de Diégo-Suarez — Antsiranana Bay — which SHOM hydrographers have described as one of the largest and best-sheltered natural harbours in the world. The bay mouth at Orangea peninsula funnels the Indian Ocean tidal signal into a wide protected body of water; the semidiurnal tide range inside is 2.5 to 3.5 metres at springs, with the larger values occurring when the Indian Ocean south equatorial tidal signal is at its peak in the March–April and September–October spring windows. For kitesurfers, Antsiranana is the most famous site in Madagascar. The consistent southerly and south-southwest trades run from April through November across the bay's open southern fetch, and multiple launch spots ranging from beginner-friendly sandy shallows to technical reef launches give advanced riders a full progression of sessions. Tide state affects the launch sites: the rocky fringe near Ramena beach is negotiable only in the upper half of the tidal range; the main sandy flats at Ramena are accessible through most of the cycle but the depth on the kite run changes meaningfully between neap high and spring low. Divers heading out to the Nosy Lonjo sea stack, the Emerald Sea north of Ramena, and the various pinnacles inside the bay time their dives around the tidal exchange at the bay mouth, which drives current over the submerged structure and aggregates the pelagic species — the feeding action is best on a moving tide rather than at slack. Fishing pirogues from Antsiranana and the surrounding villages work the bay on the flood, targeting the passes and the reef edge where current concentrates prey. The SHOM Antsiranana port file and the port authority at Diégo-Suarez are the authoritative local references. Open-Meteo Marine drives predictions on TideTurtle pages for this region, with the standard accuracy envelope of plus or minus 45 minutes and 0.2 to 0.3 metres.