Cathedral (Flic en Flac)

Flic en Flac · West Coast · Mauritius

The Cathedral at Flic en Flac is the signature dive site of Mauritius, a natural underwater cavern carved into volcanic basalt that delivers a visual experience rivalling famous cave dives of the Mediterranean and Red Sea. Located off the sheltered west coast, roughly 1.5 kilometres from shore, this site combines dramatic geological formations with healthy reef ecosystems in warm, clear Indian Ocean water. I descended along a sloping volcanic reef to around 25 metres where the entrance opened in the rock face. As I finned inside, the chamber expanded into a vast domed space that could comfortably hold a dozen divers. The ceiling rose perhaps 8 metres above, and punched through the volcanic rock were several natural openings through which concentrated beams of sunlight poured into the darkness. The light effect was genuinely breathtaking. Shafts of blue-white light cut through the chamber in diagonal columns, illuminating particles in the water and creating a natural spotlight effect on the sandy floor. The walls were covered in encrusting sponges and small soft corals in reds and oranges that glowed when caught by the moving light beams. The chamber hosts its own residents. Lobster antennae protruded from cracks in the walls. Squirrelfish and soldierfish congregated in darker corners, their large eyes gleaming red in torch light. A large honeycomb moray eel occupied a crevice near the entrance. Exiting the cavern, the surrounding reef was in excellent condition. Volcanic rock formations created a complex landscape of overhangs, ledges, and swim-throughs decorated with healthy corals. Emperor angelfish patrolled territorial routes. Hawksbill turtles rested on coral outcrops. Trumpetfish hung vertically among sea whip corals. The Cathedral's west coast location means conditions are reliably calm during most of the year, with visibility ranging from 15 to 30 metres. For divers visiting Mauritius, this is the one dive that should not be missed.