Zanzibar is surrounded by colourful coral reefs offering some of the best diving and snorkelling in the world. The shallow waters around Unguja support an impressive array of coral and marine life, including dolphins, turtles, barracuda and occasionally even sharks. Mnemba Atoll, a protected reef just off the north east tip of Unguja, is justifiably famous for the sheer diversity and number of tropical reef fish.
Many visitors, in their haste to reach the coast, often overlook diving from Stone Town, but some of the best snorkelling sites can be found around the islands just off Stone Town. Pemba has also gained a reputation as a world class diving destination offering spectacular drop offs and exhilarating drift dives, with excellent visibility. Snorkellers are spoilt for choice, with colourful reefs surrounding the coast, often within swimming distance.