While returning to port, the USS Neptune is struck by a Norwegian freighter. After a few seconds, the ship sinks to the bottom of the sea. To save those who are still alive in the submarine, the...

While returning to port, the USS Neptune is struck by a Norwegian freighter. After a few seconds, the ship sinks to the bottom of the sea. To save those who are still alive in the submarine, the Navy's Deep Submergence Rescue Vehicle (DSRV) arrives on scene with the "Snark," a small experimental submersible. The movie is adapted from the novel "Event 1000" by David Lavallee (1971).