Mnemba Island is a small, triangular island located about 3 km off the northeast coast of Unguja, the largest island in the Zanzibar Archipelago, Tanzania. It sits opposite Muyuni Beach and measures approximately 500 meters in diameter, with a circumference of about 1.5 km. The island is surrounded by an oval reef that extends 7 by 4 kilometers, designated as a Marine Conservation Area. While Mnemba Island and its surrounding reef are sometimes mistakenly called Mnemba Atoll, this is inaccurate, as an atoll is defined as an island that encircles a lagoon, which does not apply in this case.

The waters surrounding Mnemba Island serve as an important breeding ground for Green Turtles, and various migratory wading birds use the island as a secure roost. The fragile coral reef ecosystems accommodate countless fish species and microorganisms, while larger marine animals, such as Whale Sharks, Humpback Whales, and dolphins, are often found in the deeper waters.

Diving and Snorkeling Sites Around Northern Zanzibar Island and Mnemba Island Marine Conservation Area

Diving at Mnemba Island is year-round, with good conditions available regardless of the weather. Visibility of 20 to 40 meters is common.

1. Kichwani Reef: This deep, clear reef offers a drift dive from 20 to 40 meters, depending on divers’ experience. Various coral species can be found, including Mushroom, Honeycomb, Brain, and Staghorn Coral. Below 30 meters, divers may encounter a vertical wall teeming with reef fish, such as Trumpet fish and large Napoleon Wrasse. Those fortunate enough may spot Reef Sharks, Eagle Rays, and Manta Rays.

2. Wattabomi Site: Wattabomi is an excellent location for snorkelers and novice divers. Here, schools of small reef fish, Regal Angelfish, Bluestreak Cleaner Wrasse, Semicircle Angelfish, Moorish Idols, Blue Spotted Rays, and Lionfish are commonly observed. Look closely for Flounders and Soles, which lie on their sides, buried in the sand and well-camouflaged. Throughout most of the year, you can also see beautifully patterned Striped Dolphins, as well as Bottlenose, Spinner, and Common Dolphins, making it a fantastic spot for photography both above and below the water.

3. Aquarium Site: Situated at a depth of 20 meters, this site usually has a slight current. Patches of sandy bottom can be found near the reef, where you will encounter Surgeonfish, Moorish Idols, Parrotfish, Groupers, and large Hawksbill and Green Turtles, along with White Tip Reef Sharks.

4. West Gardens Site: This site lies at a depth of 12 meters and is a favorable location for snorkelers and novice divers.

5. The Big Wall Site: Located at a depth of 30 meters, which drops down to 50 meters, this site allows divers to descend along a vertical wall. As you drift silently past, you may encounter various species of pelagic fish, including Rainbow Runners, Bluefin Trevally, and common dolphin fish. The edge of the wall features overhangs and small caves, often home to lobsters.