Latitude Zero

Three men (Dr. Ken Tashiro, Dr. Jules Masson, and Perry Lawton) are trapped in a bathysphere due to seismic activity. They are rescued by the crew of the supersubmarine ''Alpha'', captained by Craig Mackenzie (Cotten), who they learn is over 200 years old (and that the ''Alpha'' was launched in the early 19th century). Mackenzie takes them to Latitude Zero to deal with the serious injuries of Dr Masson. While returning to Latitude Zero, they are attacked by a rival supersubmarine, the ''Black Shark'', captained by Kuroi (Hikaru Kuroki), who works for a rival of Mackenzie, Dr. Malic (Romero), who is also over 200 years old and has a base at Blood Rock.