The Great Barrier Reef Drain the Oceans : Season 4 Episode 9
TV-PG (self-applied) National Geographic 47m int(0)
Aired: August 23rd, 2021 @ 9:00 PM EST on National Geographic
The mysterious sinking of Australia's "Titanic", a warship on a dangerous mission, and a ROV expedition searching for clues at the bottom of the reef.