Zanzibar is reputed to have some of the best diving in the world, and the coral reef structures that surround Unguja and Pemba ensure that the marine life is abundant. Good visibility (20 - 60 metres) and there is a year-round average water temperature of 27°c Scuba divers can enjoy exciting wall dives, night dives and drift dives. In deeper waters, lush coral gardens often stretch as far as the eye can see, and large gamefish (barracuda, kingfish, tuna and wahoo) hunt together with large Napoleonic wrasse, graceful manta rays and sharks. Shallower waters are the playground of tropical fish, including a huge variety of Indo-Pacific marine fauna.
The reefs of the archipelago offer a staggeringly beautiful and varied display of marine life. Examples of most kinds of tropical marine habitat occur here, including exposed fringing reefs, rock walls, soft coral and algae-dominated reefs. The diversity of animal and plant life is hard to match, with over 50 genera of corals and 400 species of fish so far identified; many more still await determination. There are excellent examples of giant table corals, delicate seafans, whip corals, and huge stands of blue-tipped staghorn corals. Large predatory fish and turtles are common and surprisingly unaffected by approaching divers.
Pemba Island forms part of the Zanzibar Archipelago. Approximately 50 km long, it has excellent diving along its entire shoreline. Pemba is surrounded by numerous smaller islands giving rise to magnificent coral drop offs with excellent visibility. In the channels between the islands are submerged reefs, thickly crusted with a mixture of sponges, corals and seaweeds. In the water above, schools of manta rays feed on the rich supply of plankton. Also seen are napoleon wrasse, pelagic fish, turtles and sharks.