Dive Site: Greg's Wall

About Greg's Wall

Greg's Wall is an advanced dive site situated in the Radama Archipelago, off Madagascar's northwestern coast. This remote location in the Mozambique Channel ensures pristine diving conditions, with marine ecosystems largely untouched by human influence. The healthy reef evokes a sense of how coral environments appeared decades ago, offering a glimpse into a vibrant, unspoiled underwater world. The wall itself drops dramatically from a shallow reef crest into deeper channel waters, adorned with spectacular marine growth. Its remote setting, far from major population centers and tourist infrastructure, safeguards it from typical pressures, resulting in exceptional coral coverage. Dense hard corals thrive in the upper sections, transitioning to impressive soft corals and gorgonian displays at greater depths. The Mozambique Channel's warm, nutrient-rich waters foster prolific growth, with barrel sponges, sea fans, and black coral colonies of considerable size decorating the wall face. The coral diversity mirrors the rich biodiversity found across the Indian Ocean. Marine life here is outstanding, supported by the healthy environment. Schools of fusiliers and anthias swirl above the reef crest, while larger predators like groupers, trevally, and reef sharks patrol the wall. Sea turtles are a frequent sight, and during the appropriate season, humpback whales migrate through the channel, their songs often audible to divers. This abundance across the food chain underscores the site's ecological health. Access to Greg's Wall typically requires dedicated liveaboard expeditions due to its remote location. The advanced rating reflects the potential for strong currents in the channel, significant depths, and the logistical challenges of reaching such a secluded destination.

Dive site facts: Greg's Wall

Depth

5–40 m

Current

Moderate to strong

Visibility

15–30 m

Water temperature

26–29 °C

Entry

Boat dive

Level

Advanced

Dive type

Wall, coral, pelagic

Region / port

Radama Archipelago

Coordinates

-13.35, 48.2833

Conditions & Currents

Greg's Wall is an advanced dive due to its location in the Mozambique Channel, which can bring strong currents. Divers should expect variable conditions, ranging from mild to moderate or even strong currents, particularly when the channel is active. Entry and exit strategies, such as negative entries or current-assisted drifts, may be employed depending on daily conditions. While visibility often surpasses 25 meters, it can occasionally be reduced, especially during the wet season, due to increased rainfall and runoff. Thermoclines are generally not a concern given the consistently warm water temperatures, though surges might occur in shallower sections. Divers must be comfortable with current management and ensure adequate gas planning for potential exertion.

Marine life & sighting chances

Fusiliers

common

Anthias

common

Groupers

occasional

Trevally

occasional

Reef Sharks

occasional

Sea Turtles

occasional

Humpback Whales

July-September · occasional

Manta Rays

March, July, November · occasional

Hammerhead Sharks

November · occasional

Moray Eels

occasional

Napoleon Wrasse

occasional

Sweetlips

occasional

Dive profile & how the dive runs

Diving Greg's Wall typically begins with a boat drop directly onto the reef crest, which sits shallower, allowing for a negative entry if currents dictate. Divers then descend along the dramatic wall face, exploring the diverse coral growth and marine life at various depth bands. The route often follows the wall, allowing divers to drift with the prevailing current while observing dense hard corals in the upper sections and abundant soft corals and gorgonians at deeper levels. The dive progresses along the wall, with the turn point determined by air consumption and no-decompression limits, usually before reaching the deeper channel floor. Ascents are made back along the wall, with safety stops performed in the shallower, current-sheltered sections of the reef crest before surfacing for boat pick-up.

Underwater photography

Greg's Wall is an exceptional site for wide-angle photography, capturing the dramatic wall topography, vast coral coverage, and schooling fish. A wide-angle lens is ideal to encompass the expansive hard and soft coral gardens, barrel sponges, and sea fans that adorn the wall. For capturing larger pelagics like reef sharks, trevally, or seasonal humpback whales, a dome port with a wide-angle lens is essential. Strobes are highly recommended to bring out the vibrant colors of the corals, especially at depth where natural light diminishes. Be mindful of potential strong currents, which can make steady composition challenging; practice good buoyancy and brace yourself if necessary. Given the pristine nature of the site, maintaining excellent buoyancy control to avoid contact with the delicate corals is paramount for ethical photography.

Combine with nearby dive sites

• Nosy Mitsio Pinnacles

  Offers pristine coral gardens and chances for pelagic encounters.

• Nosy Tanikely Marine Reserve

  Known for abundant marine biodiversity and healthy coral reefs, though shallower.

• Nosy Komba Reef

  Provides consistent diving opportunities with healthy coral gardens.

• Radama Islands

  The broader archipelago where Greg's Wall is located, known for remote, untouched diving.

Getting there & logistics

Accessing Greg's Wall, located in the remote Radama Archipelago, almost exclusively requires a liveaboard expedition. The primary international gateway to Madagascar is Ivato International Airport (TNR) near Antananarivo. From there, domestic flights are typically taken to Nosy Be (Fascene Airport, NOS), which serves as a common departure point for liveaboards exploring the northern and northwestern dive regions, including the Radama Islands. Trip lengths for liveaboards usually range from 7 to 10 days. Due to its remote nature, specific park fees for Greg's Wall are usually incorporated into the liveaboard package. It is often combined with other sites in the Radama and Mitsio Archipelagos, offering a comprehensive tour of Madagascar's untouched northern dive sites.

Safety & environment

Diving Greg's Wall requires robust safety planning given its advanced nature and remote location. The nearest recompression chamber is likely in South Africa, meaning evacuation would be complex and time-consuming. Comprehensive dive insurance, including coverage for medical emergencies and emergency evacuation, is non-negotiable. Site-specific hazards include potentially strong and unpredictable currents in the Mozambique Channel, which necessitate excellent current diving skills and careful dive planning by guides. Depths can extend significantly along the wall, requiring conservative no-decompression limits and potentially enriched air nitrox. Divers must strictly adhere to the dive brief, maintain buddy contact, and carry appropriate safety equipment, such as an SMB and signaling devices. Marine life, while generally not aggressive, includes reef sharks and large pelagics, requiring respectful observation distances.

Who it suits — and who it doesn't

FAQ

Greg's Wall FAQ