Top 10 Dive Sites in The Comoros
The Comoros archipelago — four volcanic islands in the northern Mozambique Channel between Madagascar and the East African coast — is one of the least-visited dive destinations in the Indian Ocean. That obscurity is its most significant feature: the reefs here have not experienced the tourism pressure of the Maldives, Seychelles, or Red Sea, and the combination of volcanic topography, warm Indian Ocean water (26–29°C year-round), and proximity to some of the deepest water in the western Indian Ocean creates conditions that have produced a genuine biological wonder. The coelacanth — Latimeria chalumnae, the 'living fossil' fish thought extinct for 65 million years until its rediscovery in 1938 — was found in Comoran waters and persists here in the deep volcanic slopes that drop away from the islands. Recreational divers will not see coelacanths, but the same dramatic underwater topography that shelters them provides exceptional diving at recreational depths.
1. Mohéli Marine Park, Mohéli Island
Mohéli is the smallest of the main Comoran islands and the site of the archipelago's only formal marine protected area. The park encompasses the southern coast of Mohéli and several small offshore islets, protecting nesting beaches for three species of sea turtle (green, hawksbill, and leatherback) and a reef system in notably better health than the more populated islands. Dive depths run from the surface to around 30 metres on the wall sections. Green turtles are almost guaranteed — the park holds one of the largest green turtle nesting populations in the Indian Ocean — and the reefs show good hard coral coverage with the characteristic Indo-Pacific fish assemblage: parrotfish, surgeonfish, various grouper, and the larger predators including Napoleon wrasse. Open Water appropriate for most sites; Advanced for the deeper wall sections.
2. Chissioua Ouenefou, Off Mohéli
One of the small islets within the Mohéli Marine Park, Chissioua Ouenefou rises from deep water to the surface and produces the kind of seamount diving that aggregates large fish. The underwater topography is volcanic — rough basalt rock with hard corals established on the upper surfaces and sponge gardens in the deeper sections. Schooling fish are a feature of this site: large schools of snapper and fusiliers circle the shallower sections of the seamount, and white-tip reef sharks rest in the crevices below 20 metres. The islet's isolation makes it a dedicated boat trip rather than a casual half-day dive; plan accordingly. Advanced Open Water recommended.
3. Grande Comore (Ngazidja) Outer Reef
Grande Comore is the largest island, dominated by the active Karthala volcano. The fishing community that surrounds the island has historically put significant pressure on the reefs, but the outer reef sections — accessible by boat from Moroni — show recovery in areas where fishing intensity has reduced. The volcanic rock provides a dramatic underwater landscape, with lava formations and surge channels at depths from 5 to 25 metres. Fish life is good in the less-fished sections, and the water clarity off the northern tip of the island, away from the main port, reaches 20 metres in good conditions. The seabed here reveals the island's volcanic origin at every turn — basalt columns, lava tubes, and surge channels form a landscape unlike the typical Indo-Pacific coral reef.
4. Anjouan (Ndzuani) Wall Dives
Anjouan is politically the most turbulent of the Comoran islands but has a coastline with genuine diving potential. The western coast wall drops steeply from the reef crest at around 8 metres to recreational depth limits and beyond, with gorgonian sea fans and soft corals establishing on the steeper sections. The island sees extremely few foreign visitors for diving, which means any sites explored here are effectively undocumented in the international dive literature. Local fishermen doubled as guides for the handful of visiting divers in recent years. Marine life includes the species typical of the Mozambique Channel: sea turtles, moray eels, various grouper, and the large reef fish that appear where fishing pressure has not been relentless.
5. Coelacanth Waters, Itsundzou, Grande Comore
Off the village of Itsundzou on the southwest coast of Grande Comore, coelacanths have been documented at depths of 100 to 400 metres in volcanic cave systems on the steep outer slope. These depths are far beyond recreational diving; submersible and deep ROV surveys have documented resident populations. The recreational diving in the same area — at depths of 15 to 30 metres on the volcanic slope above the coelacanth habitat — provides its own interest: the steep volcanic drop-off, the clear water typical of this remote coast, and the knowledge that a few hundred metres below your fins something remarkable is resting in the dark. The site is a philosophical dive as much as a biological one.
6. Iconi Reef, Grande Comore
Off the village of Iconi, south of Moroni, a shallow fringing reef extends from the shore to a depth of around 18 metres before the volcanic slope deepens. The reef here is accessible as a shore dive from the village itself, making it one of the most accessible recreational diving sites on Grande Comore. Coral coverage is variable — the reef has experienced some bleaching impact and fishing pressure — but the fish life remains reasonable, and the volcanic basalt substrate gives the shallow sections a distinct appearance. A practical choice for a first dive in Comoran waters before moving to more remote sites.
7. Lac Dzialandzé, Grande Comore (Freshwater)
One of the crater lakes on Karthala volcano, Dzialandzé is a freshwater body at altitude that local divers occasionally explore. This is not conventional coastal diving but represents the extreme end of what the Comoros offers to divers willing to explore. The lake's depth and temperature profile are unusual; the submerged volcanic rock is dramatic; and the isolation of diving in a crater lake on an active volcano in one of the Indian Ocean's most remote island groups gives the experience a singularity that no reef dive can match. Not accessible to casual visitors; requires local guide arrangements and robust self-sufficiency.
8. Mbude Pass, Mohéli South
The passage between Mohéli and the small islets to the south channels tidal flow and creates a drift dive context on an otherwise calm coastline. The current here concentrates plankton and small fish, which in turn attracts the resident pelagic community: barracuda schools, occasional tuna, and — in certain seasons — manta rays. The current dive requires an experienced guide who knows the tidal timing; the window when conditions are right is relatively short. Advanced Open Water is the practical minimum. When conditions align, this is one of the more exciting dives in the Comoros.
9. Sima Bay, Anjouan
The eastern bay at Sima on Anjouan is a sheltered dive site in relatively protected water, with depths to around 20 metres on a mixed sandy and rocky bottom. The site suits divers who want to explore what Anjouan offers without the exposure of the outer coast. Stingrays rest on the sandy sections; octopus are common on the rocky areas. The sheltered water also makes it a viable site for training dives if a visiting instructor is working with locally sourced students. The marine environment here is typical of the Mozambique Channel's productive inshore waters.
10. Dzahadjou Reef, Northern Mohéli
A northern outlier of the Mohéli Marine Park diving, Dzahadjou reef offers a gentler reef profile than the southern park sites — a gradual slope from 5 to 25 metres rather than a dramatic wall — and is known locally for consistent turtle activity. Green turtles rest on the coral heads during the day and can be approached to within a few metres if divers keep buoyancy clean and movements slow. The reef is in good health relative to the Comoros average. Night dives here produce a different character from the day experience: lobster emerge from crevices, octopus hunt actively, and the reef's nocturnal fish population reveals itself.
Planning a Diving Trip to the Comoros
The Comoros are not an easy destination. Flights connect via Madagascar, Kenya, or La Réunion; accommodation outside Moroni is basic by most international standards; and the political instability that has characterised the islands periodically creates logistical complications. The best diving season is broadly the dry season from May through October, when the southeast trade wind reduces the risk of cyclone and visibility is at its best. A handful of operators based on Mohéli and in Moroni can organise diving; bringing your own equipment is strongly advised as rental gear is limited. The rewards for those who make the effort are substantial: uncrowded reefs, a remarkable natural history context, and the satisfaction of diving somewhere genuinely off the beaten track. Open the map to locate Comoran dive sites and plan access routes from the archipelago's limited entry points.