Mnemba Island is a single small island found about 3 km off the northeast coast of Unguja, the largest island of the Zanzibar Archipelago, opposite Muyuni Beach. It is roughly triangular, about 500m in diameter and about 1.5 km in circumference. It is surrounded by an oval reef seven by four kilometres in extent. These reefs have been declared a Marine Conservation area. Mnemba Island and its reef are sometimes called Mnemba Atoll which is incorrect because an atoll is an island that encircles a lagoon, which is not the case for Mnemba Island.

The surrounding waters and area around Mnemba Island are an important breeding ground for Green Turtles while a host of migratory wading birds use the island as a secure roost. The fragile coral reef eco-systems support countless fish species and microorganisms while gigantic Whale Sharks, Humpback Whales and dolphins frequent the deeper waters. 

Diving & Snorkelling Sites Around Northern Zanzibar Island and Mnemba Island Marine

*Diving at Mnemba is a year-round event, with good conditions to be found on the atoll under almost all-weather conditions and visibilities of 20 to 40 metres are the norm.

*Wattambomi is an excellent site for snorkels and novice divers. Schools of small reef fish, Regal Angelfish, BlueStreak Cleaner Wrasse, Semicircle Angelfish, Moorish Idols, Blue Spotted Rays, Lionfish are commonly seen. Take your time looking for Flounders and Soles. These fish lie on their side buried in the sand and are very well camouflaged. For most of the year, you will be treated to the beautifully patterned Striped Dolphin, but the Bottlenose, Spinner and common Dolphins are also seen in the clear waters around Mnemba Atoll. This is an excellent photographic opportunity both above and below the water.

*Kichwani Reef is a deep, clear, drift dive from 20 to 40 meters depending on the diver’s experience. Many coral species are found such as Mushroom, Honeycomb, Brain and Staghorn Coral to name just a few. Below 30 meters, a vertical wall of reef fish, Trumpet fish and large Napoleon Wrasse are commonly seen; lucky divers can spot Reef sharks, Eagle, and Manta Rays.

*The Aquarium’s depth is 20 meters. There is usually a slight current at this site. Patches of sandy bottom occur quite close to the reef with Surgeon fishes, Moorish Idols, Parrotfish, Groupers, large Hawksbill and Green Turtles along with White Tip reef sharks.

*West Gardens Site: Lies at a depth of 12 meters and is a good spot for snorkels and novice divers.

The Big Wall Site: Lies at a depth of 30 meters, which drops to 50 meters. You will descend to 30 meters drifting along a vertical wall. On your silent drift along this wonderful wall, you will be passed by different species of pelagic schools of Rainbow Runner, Bluefin Trevally, and common dolphin fish. Along the edge of the wall, you find some overhangs and small caves often filled with lobsters.

*Mnemba Island 4.5 kilometres off the north-eastern tip of Zanzibar is 500 meters in diameter and 1.5 kilometres in circumference, this tiny island is wrapped by an oval reef — known as the Mnemba Atoll — a marine conservation area.