The docu-drama reveals, for the first time, the astonishing secret events behind the Russian submarine, Red October, that went missing on March 8, 1968, taking the Soviet Union and U.S. to the brink of war.

The USS Neptune, a nuclear submarine, is sunk off the coast of Connecticut after a collision with a Norwegian cargo ship. The navy must attempt a potentially dangerous rescue in the hope of saving the lives of the crew.

During WWII, Duke E. Gifford is second in command of the USS Thunderfish, a submarine which is firing off torpedoes that either explode too early or never explode at all. It's a dilemma that he'll eventually take up personally. Even more personal is his quest to win back his ex-wife, a nurse; but he'll have to win her back from a navy flier who also happens to be his commander's little brother.

Robert Llewellyn examines the enduring appeal of submarine movies, finding a beached Cold War Russian nuclear sub on the Medway and WWII German U-boat pens on the French coast.

A German submarine hunts allied ships during the Second World War, but it soon becomes the hunted. The crew tries to survive below the surface, while stretching both the boat and themselves to their limits.

Captain Jim Leslie, a US Air Force pilot, is transferred to a remote Alaskan base not far from the Soviet border. Here he meets his old friend Harris again and falls in love with Brenda, the commander's daughter. He then comes into conflict with her fiancé, Senator Gordon Gray. At his instigation, he is sent on a dangerous mission with Harris and the navigator Hester: During a storm, the buoys deployed to locate Soviet submarines must be checked. During the emergency landing on an ice floe, Harris suffers a life-threatening injury. They are in Soviet territory, but in view of the situation Jim disregards the radio ban and sends a distress signal. A Soviet submarine appears, Harris is operated on and they are helped to get the plane ready for take-off. Arriving at the base, Jim is arrested. Brenda turns her back on him.

Based on true events, an American submarine collides into a Soviet sub of the coast of America and an ensuing standoff occurs that could lead to total annihilation.

After the Cold War, a breakaway Russian republic with nuclear warheads becomes a possible worldwide threat. U.S. submarine Capt. Frank Ramsey signs on a relatively green but highly recommended Lt. Cmdr. Ron Hunter to the USS Alabama, which may be the only ship able to stop a possible Armageddon. When Ramsey insists that the Alabama must act aggressively, Hunter, fearing they will start rather than stop a disaster, leads a potential mutiny to stop him.

Based on a true incident that occurred in 1942 when nine Nazi saboteurs were put ashore on the coast of Long Island, New York, by submarine, with orders to blow up various defense installations.