Coin de Mire, or Gunner's Quoin as it is known on old maritime charts, is a small volcanic island sitting proudly in the Indian Ocean, just 8 km north of Mauritius. Its name — French for "wedge corner" — describes the distinctive shape of its dramatic cliffs, which rise sharply from the sea and make it instantly recognisable from the northern coastline. Uninhabited and protected, this island is one of the north's most celebrated natural treasures, and for good reason: the waters that surround it are among the clearest, most pristine in all of Mauritius.
Unlike many spots that sit behind the main reef, Coin de Mire lies just outside it, which means the ocean here is refreshingly untouched. Visibility is exceptional, currents are manageable, and the marine life is abundant. It's no surprise that families, couples, and curious travellers keep returning season after season.
Most visitors reach Coin de Mire by boat excursion departing from the northern coastal towns of Grand Baie or Cap Malheureux. The journey itself is a treat — you'll cruise past turquoise lagoons and watch the island's volcanic silhouette grow larger on the horizon. Most organised trips include snorkeling gear, a guide, and often a light lunch or refreshments on board.
Once you arrive, you'll anchor near the shallow coral reef that fringes the island. The water is wonderfully clear and calm in most conditions, making it ideal for snorkelers of all ages. Children who are comfortable in the water will absolutely love it here. The reef sits at a shallow enough depth that you can observe an astonishing variety of marine life without ever having to dive below the surface — just float, look down, and let the ocean do the rest.
Expect to spend anywhere from 45 minutes to over an hour in the water, depending on your tour. Guides are typically on hand to point out highlights and ensure everyone feels comfortable and safe throughout the experience.
The coral reef around Coin de Mire is a genuine spectacle of colour and movement. Because the area sits outside the main reef and is largely undisturbed, the ecosystem here is particularly healthy and diverse. From the moment you put your face in the water, you'll be greeted by a dazzling cast of tropical characters.
Butterflyfish are among the most commonly spotted residents — their bold black-and-yellow patterns make them easy to identify, and they tend to dart playfully among the coral branches. Angelfish glide elegantly through the water, their flat, disc-like bodies catching the light as they move. You'll also spot schools of damselfish, small and spirited, darting in and out of the coral in flashes of electric blue and vivid orange.
Keep your eyes open for parrotfish nibbling at the coral, curious wrasse weaving between rocks, and the occasional sea urchin nestled in a crevice. The coral formations themselves are equally mesmerising — branching staghorn corals, broad table corals, and colourful soft corals create a natural architecture that's endlessly fascinating to explore from the surface.
The best conditions for snorkeling at Coin de Mire are generally between October and April, when the sea is calm, visibility is at its peak, and the water temperature is a lovely 26–29°C. This coincides with the Mauritian summer, so it's also the busiest tourist season — book your boat excursion in advance to avoid disappointment.
The winter months (May to September) can see stronger winds and choppier seas in the north, though calm days still occur. If you're visiting during this period, check weather conditions carefully before heading out. Morning departures tend to offer the smoothest seas regardless of the season.
Coin de Mire is only accessible by boat. Organised snorkeling and island excursions depart regularly from Grand Baie and Cap Malheureux, both of which are well-served by taxi, bus, and rental car from anywhere on the island. Full-day and half-day tours are widely available through hotels, tour operators, and local boat charter companies. Many packages include snorkeling equipment, a guide, and sometimes a BBQ lunch on board or on a nearby beach.
Coin de Mire is also known among scuba divers for its underwater landscapes. Explore nearby dive sites and dive centers on DivingMauritius.