Pemba is the other main island of the Zanzibar Archipelago, lying about 80 km north of Unguja, and it is everything that Unguja is not: hilly, densely vegetated, nearly traffic-free, and almost entirely without mass tourism. The island's interior is a landscape of clove trees, banana plantations, and steep valleys running down to deeply indented bays. It receives more rain than Unguja and stays greener year-round.
Pemba's diving is by common consensus among the best in East Africa — some argue in the Indian Ocean. The island sits in a channel between the African mainland and Zanzibar that generates strong currents, which in turn support enormous walls of coral and large populations of pelagic fish. Sharks are common, dolphins frequent, and the reef fish populations are far denser than on the more heavily visited Unguja reefs. A handful of small dive operators base themselves on the island; unlike Mnemba, the reefs here see almost no day-trippers.
Getting to Pemba requires a short flight (about 30 minutes from Zanzibar or Dar es Salaam on Coastal Aviation or Auric Air) or an unreliable ferry. The flight is worth it — Pemba is best explored by motorcycle or bicycle along quiet red-dirt roads, staying in one of a handful of simple guesthouses. It is the kind of place that travellers who have been to Zanzibar go when they want to remember what Zanzibar used to feel like twenty years ago.