To capture thrilling, face-to-face encounters with deadly great white sharks, the young thrill-seekers, Josh; his half-brother, Jeff, and Jeff's girlfriend, Megan, set off to the vast and unforgiving Australian coast to go cage-diving. As the audacious friends start filming an audition tape for an extreme reality-TV show in the relative safety of their heavy cage, a towering wave capsizes their small boat, stranding the reckless trio in the cold water. Now, as the day grows dim, and raw fear gets the best of the defenceless trio, a famished school of man-eating oceanic predators start closing in on them, turning their recording into a bloody diary of death. Do they have what it takes to survive the open water?