Trivia: Quentin Tarantino did uncredited script work on this film.
Trivia: In the beginning of the movie, where it shows a rather scenic footage of the sub about to dive, the exact shot was also used in G.I. Jane. Note that Crimson Tide was directed by Tony Scott and GI Jane by brother Ridley. A bit of sibling teamwork?
Trivia: I just saw the movie Crash Dive 2 (which is also about submarines and also involves an enemy Akula-class sub) and it has many recycled scenes from Crimson Tide. To name a few: the scene where the sub does a "snap shot" of two torpedoes, the scene of the Akula being hit, and the scene where a torpedo barely misses the heroes' sub.
Trivia: In the film, the submarine is called the Alabama. The University of Alabama's athletic teams are called the Crimson Tide.
Trivia: Viggo Mortensen's son Henry plays Weps' son, who also happens to be named Henry.
Chosen answer: The ship has a second antenna, but the radio is damaged during the torpedo attack. Therefore they have to fix it in order to use the backup antenna.