It's 1946 and Australia is recovering from WW2. When the proceeds of a bank robbery end up in the bottom of the river, Maddock and his team of thugs hire a team of professional divers to locate the gold. Led by the loveable Ernie, the dive team includes a new recruit, Clara, and diver, Jimmy. Finding the sunken car on the riverbed, their efforts are hampered by a bull shark. After Clara is almost killed in an attack, she is reluctant to go down again. With Maddock holding her team hostage, Clara is forced to confront the shark in an en effort to save her teams' lives.