In November 1984, the Soviet Union's best submarine captain in their newest sub violates orders and heads for the USA. Is he trying to defect or to start a war?
A civilian diving team is enlisted to search for a lost nuclear submarine and face danger while encountering an alien aquatic species.
A German submarine is boarded by disguised American submariners trying to capture their Enigma cipher machine.
A scientist is nearly assassinated. In order to save him, a submarine is shrunken to microscopic size and injected into his blood stream with a small crew. Problems arise almost as soon as they enter the bloodstream.