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. The Marines are (along with the United States Navy) part of the U.S. Department of the Navy.note The two service branches have shared the Department since 30 June 1834.
The scenes on the flight deck were shot on the actual Enterprise.
Scott Glenn (Mancuso) took an overnight cruise aboard USS Salt Lake City where he was treated as though he was the commanding officer, and the experience would influence his portrayal of Mancuso on the Salt Lake City's commanding officer, Thomas B. Fargo. 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 film, shots of the Soviet submariners in rafts clearly show USS Gary (FFG-51).
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
The plane that crashes into the Enterprise is supposed to be an F-14, but what is shown is archival footage of an F-9 crash — from the 1950s.
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: 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 — whom he had previously co-starred with in Never Say Never Again — 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.note Ironically, Brandauer and Connery would end up appearing together in The Russia House, which came out later that year
Technology Marches On: 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.
Troubled Production: A long standing Hollywood rumor was that Sean Connery's hairpiece cost $50,000 dollars. Many years later, a producer admitted that that number came from the cost of reshooting several scenes with the original hairpiece, which sported a small ponytail that Connery decided looked ridiculous after a few days of shooting.
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.
In the script, the opening crawl was originally supposed to set the film in 1991 rather than 1984, mentioning the forced retirement of Mikhail Gorbachev and the Soviet Defense Minister taking power, leading to renewed Western fears of Soviet aggression in the Cold War. Had this crawl been kept, it would have been an eerie prediction of the August coup that attempted to oust Gorbachev from power, prior to the collapse of the Soviet Union in December 1991.