Yampi Sound, portion of the Indian Ocean off the north coast of Western Australia, between King Sound and Collier Bay. It contains the four island clusters of the Buccaneer Archipelago, named for the buccaneer William Dampier. The largest of the islands are Koolan, Irvine (with extensive underwater iron deposits), and Cockatoo. Deposits of high-grade iron ore and other minerals are found on the islands. On Cockatoo, named after the white birds that abound there, hematite (an iron ore) has been mined since 1951; mining on Koolan began in 1965. Extreme tides on Yampi Sound make navigation difficult. The sound was named in 1838 by Lieutenant John Lort Stokes (who surveyed the coast aboard HMS Beagle) and derives from an Aboriginal word meaning “freshwater.”