Based on an incident that occurred off the coast of Florida in 1973, this film tells the story of four men who find themselves trapped in a mini-submarine in the ocean depths.

Lee J. Cobb
as Victor Bateman

Martin Balsam
as T.C. Hollister

Joshua Bryant
as Sam Wallants

Paul Michael Glaser
as Jack Beech

Barra Grant
as Grace Wallants

Warren J. Kemmerling
as Cmdr. Prestwick (as Warren Kemmerling)

Cliff Potts
as Gordon Gaines

Laurie Prange
as Chris Moffet

Phillip R. Allen
as Lt. Cmdr. Hanratty

Redmond Gleeson
as PO1 Stanton