A lone rock in open sea where giant manta rays come to be cleaned, with grey reef sharks, huge schools of jack and barracuda…A lone rock in open sea where giant manta rays come to be cleaned, with grey reef sharks, huge schools of jack and barracuda, and the largest anemone fields in the Andaman Sea at nearby Rocky One. Almost nobody dives the Mergui. The archipelago's 800 islands were closed to foreigners until 1997 and remain barely visited, home to the Moken sea nomads who spent their lives on boats and whose knowledge of the sea let them read the 2004 tsunami and survive it almost intact. Anchorage: Liveaboard only; the Mergui archipelago is largely uncharted for yachts. Hazards: Remote with no chamber and no rescue. Permit and political situation both need checking before committing, and conditions can be rough. Meer