Moors Arch Deep is a captivating deep dive site located off the northern coast of Mauritius, not far from the dramatic island of Coin de Mire. The site takes its name from the impressive natural rock arch formation that forms the centrepiece of the dive, dropping into open water at significant depth. The architecture of the reef here is genuinely spectacular — towering walls of coral-encrusted rock frame the arch, channelling currents and concentrating marine life in remarkable density. This is a dive for those with advanced certification and solid buoyancy control, as the depths involved demand both experience and discipline.
The site is accessible from Grand Baie and the northern dive centres, typically reached by boat in 20–30 minutes depending on sea conditions. The upper sections of the reef begin at around 18–20 metres, with the arch structure itself descending toward 30–40 metres at its deepest points. Visibility is frequently exceptional in this part of Mauritius, often exceeding 25–30 metres, which allows divers to fully appreciate the scale of the arch and the surrounding terrain.
The deep, current-swept environment of Moors Arch Deep supports a rich and diverse ecosystem. The arch walls are festooned with wire corals, black corals, and large gorgonian sea fans that reach outward into the current to catch passing nutrients. Encrusting sponges in vivid hues of orange and yellow add to the visual drama.
The concentration of life here is directly linked to the currents that sweep through the arch — these currents bring nutrients and attract the full food chain, from tiny planktivores to apex predators.
Moors Arch Deep is rated as an advanced dive site due to its depth and the potential for current. Conditions can vary considerably depending on tidal patterns and seasonal wind direction. On calmer days with light current, the dive is manageable for confident advanced divers. When currents are running, the site becomes a drift dive experience that demands excellent buoyancy and situational awareness.
Water temperatures in northern Mauritius range from around 24°C in the cooler austral winter months (June–August) to 29°C in summer (December–March). A 3mm wetsuit is generally comfortable year-round, though some divers prefer a 5mm suit in winter at depth. Surface conditions are generally best in the morning, as trade winds tend to pick up through the afternoon.
The best months to dive Moors Arch Deep are generally October through December and April through June — the shoulder seasons that bookend the hot, wet summer and the cooler, windier winter. During these periods, seas are calmer, visibility is at its finest, and water temperatures are comfortable. Summer months (December–March) can bring reduced visibility due to plankton blooms and rougher surface conditions, though this period also coincides with increased pelagic activity. The winter months (June–August) offer cooler but very clear water.