Chole Bay is blessed with a number of excellent dives within the Bay, ensuring diving in almost any weather, as well as easy access. Visibility varies with the wind and tides, and is generally poor on outgoing tides as there is the normal accumulation of organic and granular matter in the water. The diving is tide-dependent for this reason and also to avoid strong currents at the dive sites which are close to the mouth of the Bay (Kinasi Pass). We usually dive on the full low, full high or on the incoming tide for the Kinasi Pass drift dive and the Chole and Kinasi walls.
 
Almost all Mafia's best diving is at depths of less than 30m so it is a sport diver's paradise. The reefs of the archipelago offer a staggeringly beautiful and varied display of marine life. The excellent condition and high diversity of the reefs stimulated the creation of Mafia Island Marine Park, Tanzania's first marine park. 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 460 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.
 
The best dives from Utende Beach, Mafia
 
There is diving inside and outside the lagoon of Chole Bay. the best outside dives are wall dives but can be undertaken only when weather and tides permit, as the Kinasi Pass can be treacherous on outgoing tides and should not be contemplated. To the south of Kinasi Pass there are some bank reef dives. The best time of the year foir these dives is in December - March inclusive.
 
All diving is tide dependent in the lagoon and is therefore effectively drift diving. Incoming tides are preferred for best visibility, or on full slack or low slack.
 
Blue World Diving uses local mashuas for its activities and these are usually sailed back to base after diving. this minimises pollution and maximizes the enjoyment of experiencing a traditional sailing dhow or jahazi.
 
Some examples of our dives follow:
 
Introductory dives
 
Milimani Reef
MAX DEPTH: 21 M
AVGE DEPTH: 12-14 M
TYPE OF DIVE: DRIFT DIVE OVER BANK REEF
 
A sloping reef starting at 6 m on a full tide. the dive starts at a sandy bottomn facing the reef. a wide variety of hard and soft corals and abundant reef fish as this is a nursery area. There are vast schools of immatures and many species here. an excellent dive, especially for those interested in variety and detail, and an excellent introductory dive for those who have not dived for a while.
 
Kinasi Wall
MAX DEPTH: 23 M
AVGE DEPTH: 15 M
TYPE OF DIVE: DRIFT DIVE ALONG THE FACE OF A BANK REEF.
CHOLE WALL
MAX DEPTH: 18 m
AVGE DEPTH: 9-12 m
TYPE OF DIVE: SLACK OR DRIFT DIVE

A sloping bank reef that starts at about 8 m. the dive starts from amix of sand and small limestone pebbles and climbs up the reef. There is a great variety of hard corals and colourful soft corals. There is an abundance of fish feeding here on this rich reef which thrives on the inflow to and outfall from Chole Bay. Great schools of juveniles. Spectacular species abundance, and at the end of the dive huge coral heads ("bommies" to explore. An excellent dive for the diver interested in the unusual and the small, fascinating life forms on a reef.
 
The corals, hard and soft, change all along the wall so that the diver experiences a full array fo corals and fish. Best enjoyed slowly so that the diver can look down and up, as well as away from the reef, to observe passing pelagics, a good place to spot Hawskbill turtles. Very clourful soft corals and the reef ends in a series of 'bommies' and the diver ends the dive in a coral garden at 3-6 m. This bank reef is a breeding ground and very often has astoundingly dense schools of immatures.
 
Adventure Diving
 
Kinasi Pass and the Pinnacle
Juani reef
MAX DEPTH: 22 m
AVGE DEPTH: 12-14 m
TYPE OF DIVE: SLACK OR DRIFT DIVE

This is another sloping bank reef built on ancient Porites deposits. Again an abundance of soft corals with a variety of colours: red, orange, yellow, blue and mauve. There are coral heads, rock outcrops and overhangs to explore.

This is a good place to spot Green and Hawksbill turtles, and there is a great number of batfish. Again the outer side of the reef is cruised by predatory pelagics and the diver should watch for passing barracuda, giant trevalley, kingfish, wahoo and tuna.

This can be an excellent drift dive, taking the diver from the inner side around this curving reef towards the south.

MAX DEPTH: 26 M
AVGE DEPTH: 15-16 M
TYPE OF DIVE: DIVERSE DRIFT DIVE OVER REEF AND WALL DERIVED IN STIFF CURRENTS.
 
This is Mafia's premier dive and offers great variety in both the reef structure - bank, small walls, caverns and overhangs - and fish. Bigger pelagics will be found as well as a brace of very large potato cod. schools of juvenile barracuda and carangidae. a great range of corals and sponges. the dive starts at the pinnacle rock in Kinasi Pass. The 'pinnacle' is an ancient porites spire, that is home to a huge moray and giant bat fish. the diver drifts to the west of the pass after leaving the pinnacle and will meet a wall and bank reef, with overhangs and caverns, between 18 and 26 m. Schooling juveniles and adults congregate for feeding on the incoming tide.
 
The dive should be made at least three times to appreciate it and can be completed a number of times without passing over the same area.

Jina Wall
MAX DEPTH: 24 M
AVGE DEPTH: 15-16 M
TYPE OF DIVE: SLACK OR DRIFT DIVE
 
The top of this wall dive starts at 8 m and the wall drops striagnt to a base at 23 m. Sponges and soft corals on the wall and caverns, arches and overhangs near the base, which peters out to a sandy gravel bottom. The wall is an ancient porites bank constantly scoured by ocean swell.
 
Large pelagics to be seen off the wall so the diver is advised to keep looking above and out to sea. Green and Leatherback turtles frequent this area for breeding. an excellent diversity of fish feeding on the top and at the bottom of the wall. Especially interesting for parrot fish and humphead wrasse.
 
Dindini Wall
MAX DEPTH: 25 M
AVGE DEPTH: 15-16 M
TYPE OF DIVE: DRIFT DIVE OR SLACK
 
A similar wall dive to that at jina and usually done as the second dive on an outside excursion. The wall is off the continuation of the same reef north of Kinasi Pass. This area seems to be more of a breeding ground with greater abundance of juveniles.
 
Small caves and overhangs to explore for rays.
 
Snorkelling
 
Chole Wall
This is both a dive and snorkel site. It is another bank reef that joins the Kinasi Wall but lying north-east:south-west, also about 800m long. A steep bank of coral descending to 15 m, usually with excellent visibility, and ending in coral rubble and sand. A panorama for the diver as there is a startlingly rich tapestry of corals enveloped in clouds of tiny fish, dominated by colourful damselfish and fusiliers; numerous butterflyfish and angelfish. Especially interesting for the many species of colourful nudibranchs and flatworms. This is an excellent night or introductory dive. A great dive full of interest.
 
Coral Gardens
A very large area of beautiful coral outcrops or "bommies", lying in a wedge behind the Kinasi and Chole walls. The coral is very densely packed and continuous behind Kinasi wall; elsewhere the coral is separated by seagrass and sand patches. This is an excellent site for photography with a very high diversity of fish, colourful corals and anemones and the shallow water makes visibility excellent. This is a shallow water dive, often undertaken as the last phase of one of the wall dives. Excellent for snorkellers behind Kinasi Wall at low tide.
 
The Coral Patches
This site comprises three extensive and spectacular coral patches at 9 to 17 m that are separated by sand channels. The many species of coral are packed around the ancient Porites formations. There are a large number of dense shoals of fish, equalled only by Kinasi Pass. A peculiarity is the occurrence of large numbers of spotted garden eels, so named for their habit of living together in "gardens" in the sand around the coral.
 
Kinasi Pass islets
The two larger islets in the main Kinasi Pass (Kisiwa Kubwa and Kisiwa ndogo) are superb snorkelling sites with protected anchorages in sand on the inner, Bay side. There are scattered "bommies" and shallow reefs between and around the islets. Lionfish and the Titan triggerfish are very common. Open-billed storks, hadada ibis, little egrets and fish eagles are resident on the islets. A small pool, hidden in the centre of the largest islet, can be reached by swimming through a narrow channel in the rock. Small groups of nocturnal cardinal fish lurk in the shady crevices. The "bommie" adjacent to the largest islet falls away to about 15m and houses a fascinating complex of corals and fish.
 
Excursion diving and snorkelling
 
Mange reef
 
This is a fantastic day excursion that we make in our sailing dhows; we stay out for a picnic lunch and relaxation. The sand bar is absolutely beautiful with is bleached white sand and is perfect for the sunbathers; we put up a sun-shade shelter for protection against the sun.
 
In the shallows are some of the most beautiful stands of branching staghorn corals with colourful juveniles, best appreciated by snorkeling. Large expanses of shallow coral and sand patches with brilliant illumination for superb snorkeling. On the Channel side the reef slopes away to a depth of 28 m and is a fantastic double dive on the day excursions we make to this sand cay and reef.
 
Darusi
 Darusi is an islet with its own complete fringing reef and is a snorkel site where it is impossible to get visitors out of the water…the variety of habitats and the ranbge of things to see is quite amazing, as the snorkeller slowly circumnavigates the islet, which is an ancient Porites reef. The site is close to Miewe Island so we often picnic on Miewe after a session in the water at Darusi. There is lovely swimming and snorkeling at Miewe also, where coral bommies grow in a field of beautiful white sand.