A collision with a freighter sinks the nuclear submarine U.S.S. Neptune, leaving it stuck on an undersea ledge. With only 48 hours of oxygen remaining, the captain (Charlton Heston) and crew find their only hope for a rescue lies with a less-than-by-the-book Navy officer (David Carradine) and his experimental diving craft. Based on the novel by David Lavallee, this intense drama co-stars Stacy Keach, Ned Beatty, Ronny Cox; look for Christopher Reeve in his feature film debut. 111 min. Widescreen; Soundtrack: English; Subtitles: English.