The seas around the Andaman Islands are some of the world’s most unspoiled. Marine life is abundant, with an estimated 750 species of fish existing on one reef alone, and parrot, trigger and angel fish living alongside manta rays, reef sharks and loggerhead turtles. Many species of fish and coral are unique to the area, and fascinating ecosystems exist in ash beds and cooled lava based around the volcanic Barren Island. For a quick taste of marine life, you could start by snorkelling; most hotels can supply masks and snorkels, though some equipment is in dire need of replacement. The only way to get really close, and venture out into deeper waters, is to scuba dive. The undisputed home of diving is Havelock, with eight centres up and running at the last count, and there are also operators on Neil, Long and South Andaman. Since 2013 the decompression chamber at the naval base in Port Blair has been open to any divers with suspected bends, boosting safety.