Pemba sits north of Zanzibar in the Indian Ocean and feels genuinely apart from the tourist circuit — fewer dive boats, fewer crowds, and reef systems that reward the effort it takes to get here. The island's walls are the main draw: sheer drop-offs that plunge from around 10 metres down past 40 metres into deep blue, draped in soft corals, sea fans, and barrel sponges in remarkable health.
Visibility regularly hits 20–30 metres, sometimes more, and the water has that particular Indian Ocean clarity that makes colours pop even at depth.
Currents can run strong, particularly along the outer walls at Mesali Island and around the northern tip at Ras Kigomasha, so this is not the place to rock up with an Open Water card and expect relaxed drifts. Advanced certification is sensible, and experience reading water before you jump is genuinely useful.
That said, the same currents are why the reef is so intact — they bring nutrients, discourage anchor-happy boats, and have kept bleaching pressure lower here than in parts of the wider Tanzanian coast, though the 2016 and 2024 bleaching events did leave their mark on shallower sections.
Operator options are limited compared to Zanzibar. A handful of small live-aboard-style dhow trips run out of Chake Chake and Mkoani, and a couple of lodge-based dive centres offer day boats, but don't expect a slick resort operation. Green turtles are reliably spotted on most dives, humpback snappers school along the walls, and dolphins are common on the surface crossings. Whale sharks pass through seasonally.
Best diving runs from October through March when seas settle and visibility peaks; Advanced Open Water or equivalent is strongly recommended.