Trivia: Paramount Studios essentially rented a US submarine to be in the movie. The USS Houston (SSN 713) played the USS Dallas and the surface scenes were filmed off of Long Beach, CA and Port Angelas, WA. Two crewmembers off the Houston were actually given very small speaking parts in the movie.
Trivia: The Alfa-class submarine Konovalov commanded by Captain Tupolev is named after Soviet Rear Admiral Vladimir Konovalov. In March 1945, he sunk the German luxury liner Goya in the Baltic Sea on its way to Kiel, killing 6220 East Prussian refugees out of 6385.
Trivia: The US submarine used by Paramount Studios, during the filming, accidentally sunk a tugboat when getting into position to film a scene. One of the submarine's radio antennas snagged the tow cable between the tug and a barge and this pulled the tugboat underwater. One person died.
Trivia: 'Heathrow' at the beginning of the film is actually Los Angeles International Airport; just with a neon sign (which doesn't exist at the real Heathrow), and shot at night to cover up the rest of it.
Trivia: Because of its role in this film, the crew of the real USS Dallas adopted "The Hunt Is On" as the unofficial ship's motto.
Trivia: The scene where the "DALLAS" is shown "leaping" out of the water is actually USS HOUSTON just outside the Straits of Juan Defuca, 600 yards off the Starboard side of a US Frigate, conducting an intentional full speed emergency blow that was practiced 6 times to get the timing and positioning right for the 6 cameras arrayed on the surface warship. Each practice was done without an actual emergency blow, the submarine "drove" to the surface. On the final run the HOUSTON alerted the crew 1 minute before actually initiating the emergency blow. Positioning was done without the benefit of GPS, which was not available.
Trivia: The USS Reuben James that intercepts the Red October (when she surfaces to let the crew off) figures prominently in Tom Clancy's "Red Storm Rising".
Trivia: Sean Connery originally declined the part of Marko Ramius, thinking that the story took place after Gorbachev rose to power and began the policies of detente and perestroika. After he was faxed the note shown at the beginning of the film declaring the events take place before Gorbachev, he accepted the role.
Trivia: Throughout the shooting of the Jack Ryan HELO drop scene, the OOD would set the submarine up on specified course and speed, then duck down to prevent interfering with the scene. At one point the "Dallas XO" actually fell over the side of the sail because the stunt man's harness broke - it was his personal harness, not a real Navy safety harness. The OOD immediately jumped up, announced "Man overboard", realised the stuntman had only fallen to the top of the port sailplane and stopped the submarine. The stuntman - dazed, slowly rolled over, swore a couple of times and hauled himself (with help) back into the cockpit. He was provided with a ship's safety harness (that he ended up taking with him) and we set up to do the scene again. It was successfully completed.