Sea Hunt

A jet plane suddenly goes out of control, plunging to the bottom of the sea. When ex-Navy frogman Mike Nelson dives to locate the wreck, he's amazed to find the pilot still alive, imprisoned in the watertight cockpit.

An explosion rocks a Wyoming coal mine, flooding the shafts and costing the lives of 30 miners. Deep in the shafts, Mike discovers two survivors trapped in an air pocket.

When deep sea divers go too deep or stay down too long, the resulting narcotic effect is called 'Rapture of the Deep.' When a party of skin divers falls victim to the 'rapture,' one of them becomes homicidal.

Before Mike Nelson can investigate the disappearance of two geologists, the sea washes one of them upon the beach. His body bears marks made by the suction valves of a giant octopus. Mike knows an octopus rarely attacks.

Mike Nelson rescues an unidentified girl from drowning. The Immigration Department suspects she's an illegal alien. The girl confesses she was towed into the country underwater in a sea sled operated by a ring of border runners.

Lovely Kay Dalton, terrified of the sea, persists in skin-diving. Her objective is to recover a cache of stolen diamonds on the ocean floor. Although Mike Nelson warns that she will never conquer her fears, Kay refuses to quit.