Cathedral (Flat Island) – Northern Offshore Islets Dive Site

Site Overview

Cathedral (Flat Island) is a sloping underwater cavern dive site in the Northern Offshore Islets region of Mauritius, situated in the warm tropical waters of the Indian Ocean along one of the most beautiful reef-fringed islands on Earth. The site features depths from 5 to 25 meters with an average depth of 15 meters, offering an immersive underwater experience showcasing the extraordinary marine biodiversity of the Mascarene archipelago. Renowned for its vibrant coral reef ecosystems, Cathedral (Flat Island) attracts divers seeking encounters with Lionfish, Giant Moray, Nudibranch and other remarkable marine species throughout the year. The reef formations create diverse habitat zones supporting rich communities of reef-dwelling organisms and pelagic visitors that patrol the open water beyond the reef edge. The tropical Indian Ocean environment with warm water temperatures and generally excellent visibility creates ideal conditions for extended exploration and photography. Visibility typically ranges between fifteen and thirty meters during the optimal diving season. Water temperatures range from twenty-two to twenty-eight degrees Celsius depending on season. Cathedral (Flat Island) consistently ranks among the top dive sites in the Northern Offshore Islets region, drawing repeat visitors who return to observe the seasonal changes in marine life activity and the ever-evolving coral landscape that makes Mauritius a premier Indian Ocean diving destination.