Cut-price cash-in that shamelessly plunders the plots of Under Siege and Crimson Tide, though the end result is not unentertaining. Michael Dudikoff is the special agent who becomes America's last hope when a gang of crazed terrorists hijack a nuclear submarine and threaten to turn its arsenal on Washington. Frederic Forrest provides a bit of class, while the claustrophobic direction is by Andrew Stevens, better known for such erotic thrillers as Illicit Dreams and A Woman Scorned.

The crew of the nuclear submarine USS Ulysses rescues supposed victims of a boat disaster, but the victims turn out to be terrorists intent on capturing nuclear weapons aboard the sub. Only a former SEAL, now a submarine consultant, can save the crew by sliding aboard while the sub is underwater. The term "crash dive" refers to the sudden dropping of a sub to escape detection, an act that a nuclear sub is never supposed to make. Of course, it comes into play in this film.