[[folder: Film ]]
* BackedByThePentagon: The scenes on the flight deck were shot on the actual ''Enterprise''. Scott Glenn (Mancuso) also spent a month aboard ''USS Salt Lake City'' where he was treated as though he was the commanding officer. According to director John [=McTiernan=] he came back completely different, very soft-spoken and calm, with a manner he described as being similar to a college president.
* FakeRussian: It's a Hollywood flick, so it's a given that many of the major Russian characters were played by non-Slavic actors. The most obvious is Creator/SeanConnery as Lithuanian-born Captian Ramius, who doesn't even try to alter his Scottish accent. Averted, though, with most of the Soviet extras since most had obviously Slavic features.
** [[Series/StarTrekTheNextGeneration Dr. Crusher]] is Jack Ryan's wife.
** Captain Tupelov is [[PiratesOfTheCaribbean Bootstrap Bill Turner]].
** [[Film/FerrisBuellersDayOff Ed Rooney]] moonlights as a former submarine captain and current engineer when he's not the principal of a high school.
** The doctor on the ''RedOctober'' is none other than TimCurry.
** The pilot talking about "blowing chunks" is comedian Rick Ducommun.
** And, of course, [[SeanConnery James Bond]] is now a [[strike:Russian]] Lithuanian nuclear ballistic missile submarine captain.
** Borodin apparently did get to Montana [[Film/JurassicPark where he dug up dinosaurs.]]
* TheOtherMarty: Klaus Maria Brandauer was originally cast as Ramius, but two weeks into filming he had to quit because of a serious injury (he broke both his legs in a car accident). He recommended SeanConnery, with whom he starred in ''Film/NeverSayNeverAgain'', to take over the role.
* PropRecycling: The teddy bear Jack Ryan gets his daughter at the end is the same teddy bear John [=McClane=] was bringing for his kids at the beginning of ''Film/DieHard'', also directed by John [=McTiernan=].
* StarMakingRole: For Alec Baldwin.
* WhatCouldHaveBeen: KevinCostner turned down the role of Jack Ryan. Creator/HarrisonFord had also turned down the role, because he felt the script focused more on Ramius than Ryan, [[TheOtherDarrin but he would take the role]] for the sequels ''Film/PatriotGames'' and ''Film/ClearAndPresentDanger''.
** Acclaimed Austrian actor Klaus Maria Brandauer was originally cast as Marko Ramius, and participated in the production process to the point of getting costumes fitted and attending several rehearsals. And then he was in a car accident and broke both of his legs. It was at Brandauer's suggestion that SeanConnery was cast to replace him. Had Brandauer been able to finish the film, it would have had a very, very different feel to it than the actual finished product.
* Kamarov boasts about being able to fly a plane with no windows in the Alps if he has a stopwatch and a compass. This is actually a real navigational method known as Dead Reckoning. If you know how fast you are going, what direction you are traveling in, and how far you need to go to get to a particular point, you can indeed use a compass and a stopwatch to reliably get there, barring unobserved changes in weather. You wouldn't normally use it to navigate through a ''canyon'' though. Submarines, for obvious reasons, use this technique far more often than airplane pilots, as submarines lack windows to see outside with.