- Actor Allusion: Jordan Tate is "Miss July '89" — actress Erika Eleniak, who played her, was Playboy's Playmate of the month of July 1989 in real life. She was even wearing a naval-themed outfit in her centerfold.
- Completely Different Title:
- France French: "Trap on the High Sea"
- Québec French: "Battleship in Peril"
- Not Screened for Critics: At the time of its release, this was the highest-grossing movie not to have been pre-screened for critics.
- Playing Against Type: Tommy Lee Jones, usually a quippy but stern lawman or soldier, clearly has a ball playing a snarky, unhinged terrorist. Also, Glenn Morshower, who would be more well-known for his Reasonable Authority Figure roles, plays an arrogant Jerkass naval officer.
- Production Posse: Andrew Davis previously directed Seagal in Above the Law (1988) in 1988, followed by directing Tommy Lee Jones in The Package the next year. Davis's involvement sparked Jones into joining this film; their next endeavor the following year netted Jones an Oscar.
- Those Two Actors: Joseph F. Kosala is in many Andrew Davis films, though usually with Ron Dean.
- Uncredited Role: Steven Seagal did some uncredited rewrites to the script.
- Wag the Director: Seagal claimed in an interview that the character played by Erika Eleniak was not included in the original screenplay and that he personally suggested the inclusion of a stripper as a sidekick to add some humor to the film.
- What Could Have Been:
- According to a claim made by Jenny McCarthy during an interview, she was offered the role of Jordan Tate but declined because it would have required nudity. This was before McCarthy's days as a Playboy Playmate, when she was trying to make it as a legitimate actress.
- The original script, then called Dreadnaught, was at one point offered to Fox as a possible Die Hard 3, but ultimately rejected and another script, Troubleshooter, was bought instead (and abandoned when Under Siege went into production and a new script written).
- Working Title: Dreadnought.
Trivia / Under Siege