Eagle rays lay in stacks on the deck of the S.S. Yongala. Giant Queensland grouper patrol the stern. Sea snakes, turtles and clownfish also congregate on this 358-foot steamship downed by a 1911 cyclone in what is now Australia’s Great Barrier Reef Marine Park. Find it 12 nautical miles off Cape Bowling Green, Queensland. Thanks to its depth of 28m and the likelihood of a current – which helps attract schools of trevally – it is an advanced dive.