Drain the Oceans S04E09 - The Great Barrier Reef

What secrets lie beneath the waters of the world's largest coral reef? Dive the SS Yongala, a passenger/cargo ship sunk in 1911 during a cyclone, and the HMS Pandora, sunk in 1791 after striking the reef with captured mutineers from the HMS Bounty. Also, follow an expedition to map the reef and explore its geologic history