Actor-Shared Background: Sean Connery and Scott Glenn both served in the navy before becoming actors. Connery served in the Royal Navy, Glenn served in the United States Marine Corps, which is part of the US Department of the Navy.
Backed by the Pentagon: 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. The Navy was fully onboard for the movie because they were hoping The Hunt for Red October would do for the submarine service what Top Gun had done for Naval aviation. In a way it worked, the crew of the realUSS Dallas adopted the films tagline, "The Hunt is On" as the boat's unofficial motto.
Blooper: The movie is set in late 1984, and there are a couple of goofs in the setting:
The USS Reuben James (FFG-57) wasn't commissioned until 1986.
In the scene introducing Jack Ryan, he is preparing for a trip to the United States. At one point, he puts a copy of the United States Naval Institute Proceedings into his briefcase. The issue in question was a special issue focusing on submarines and anti-submarine warfare, making it a good fit for the movie—except for the minor little detail that it was the October 1987 issue...
Jonesy says that they have six Typhoon-class submarines in the computer. While it's true that the Soviets built six Typhoons, only three had been launched by the end of 1984. Two more were still under construction, and one hadn't been started yet.note This blooper actually extends to the book, written in 1984, where the October is explicitly stated to be the seventh submarine of the Typhoon class
Cast the Expert: Some of the extras playing the USS Dallas crew were actual submariners.
Descended Creator: Director John McTiernan came up with the idea that screenwriter Larry Ferguson play USS Dallas's COBnote Chief of the Boat: a submarine's senior enlisted sailor after watching Ferguson play all the parts in the script during pre-production. Hilariously, Ferguson only found out about this after seeing his name on the call sheet and then took advantage of his position and rewrote the script so that he'd be present for nearly every scene set on the Dallas.
Fake Russian: It's a Hollywood flick, so it's a given that many of the major Russian characters were played by non-Slavic actors. Joss Ackland, Sean Connery, Tim Curry (United Kingdom), Sam Neill (New Zealand), Stellan Skarsgård (Sweden), Tomas Arana (United States) and Ronald Guttman (Belgium) all play Soviets. The most obvious is Sean Connery 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.
Follow the Leader: Plot-wise, averted, since it's nothing like Top Gunnote the novel it's based on was released while Top Gun was being produced, but production-wise, this trope is played straight, since the Navy hoped this film would do for submarines what Top Gun did for naval aviation.
The Other Marty: 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 Sean Connery 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.
Technology Marches On. Inverted. The crew of the Red October is shown to be using flat-screen and touchscreen displays (note the absence of valves and keyboards) that are more than 30-years more advanced than almost all of what was possible when the film was made, and some of which is barely possible today (2016).
A whole lot of details of the Typhoon-class missile submarine, such as the fact that Real-Life Typhoons don't have a missile room, falls under this. Other details tend to fall under the Critical Research Failure heading.
Uncredited Role: John Milius did uncredited work on the script, writing a few speeches for Ramius and all of his Russian dialogue. He was asked to rewrite the whole film but was only required to do the Russian sequences.
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 and even if they had windows the lack of light at the depths at which they operate would make sight a very limited navigational tool.