Film/DieHard [-[[DieHardOnAnX ON A BOAT!!]]-] One of Creator/StevenSeagal's greatest films. It was released in 1992.

Casey Ryback (Seagal) is [[AlmightyJanitor a valued cook]] on the USS ''Missouri'', which is undergoing one last party in Pearl Harbor before it goes to UsefulNotes/SanFrancisco to be decommissioned. The captain of the ship wanted Seagal to show up in his dress whites with full decorations, but he refused; he eventually said that the captain's birthday was tomorrow and he needed to make bouillabaisse for it, which lets him off the hook.

The captain's birthday is coming, and a surprise party is arranged. Food will be flown in, and so the pesky cook has to be LockedInAFreezer -- though not before the bouillabaisse is spat on and he attempts bodily harm on the XO making the plans. He is guarded by someone on orders not to let him out or listen to him. He isn't let out...

Anyhow, this is an elaborate surprise party. There is a band featuring Tommy Lee Jones and a cake containing Miss July. Everyone is allowed off shift -- though the captain didn't want that. And there's a clown car's worth of mercenaries ready to take over the ship once everyone's had enough champagne. That's right -- a hijacking!

The captain and operations officer are killed; most of the rest of the crew is locked into the forecastle, and a few other sailors get locked in the engine room. The hijackers now have control of a ship with nukes on it. It occurs to them that the kitchen, where our cook is, is not blocked off from the weapons room, so they send someone in to finish off the pesky cook...

Of course, [[ChefOfIron the pesky cook kills him first]], and leaves a bomb in a microwave when he finally escapes. He sneaks up to the captain's room, finds him dead, and finds the cake with Miss July in it, unopened. She's alive, but she's missed everything. She's also a self-proclaimed pacifist and TheLoad...

The XO then finds the cook's service record, which had been locked in the Captain's "eyes only" safe. When they do find it, they learn that he was a Navy SEAL, one of the best ever, who, after a [[http://en.wikipedia.org/wiki/Operation_Nifty_Package#Military_execution mission in Panama]] went wrong, lost all his ranks, leaving him only qualified to be a yeoman -- or a cook. Unfortunately for them, he still has the ''skills'' of a SEAL...

They try to keep to the plan anyway -- the plan being to transfer the nukes to a sub that the CIA thought had been destroyed by mercenaries. The leader of the mercenaries in question is the band leader helping with the hijacking.

Good triumphs eventually, but it triumphs messily.

It has a sequel, ''Film/UnderSiege2DarkTerritory'' (1995).

!!Tropes that appear in the film series:

* ActionGirl: Jordan starts off as a quivering mess but evolves into this trope.
* AffablyEvil: Strannix is very much this, before his VillainousBreakdown.
-->'''Strannix:''' (looking at the carnage Ryback has left behind) Doumer, Doumer, Doumer... why didn't you ''hire'' this person? I don't know what his price would have been but it would have been ''worth'' it.
* AlmightyJanitor:
* BaitAndSwitchGunshot: As Doumer is about to shoot Chief Ryback, several shots ring out and Doumer falls to the deck dead. Behind him is standing Jordan Tate (Erika Eleniak), Ryback's LoveInterest, with a gun in her hands.
* BerserkButton: It's not really a good idea to spit in Ryback's soup. He takes it kind of personally.
* {{BFG}}: The 16" guns of the Missouri. Which Ryback uses to sink the sub.
%%* BigBad: Strannix.
* BigGood: Admiral Bates is presented as this in both films. He's of the Joint Chiefs of Staff, and takes control of HQ for the good guys. In the first film, he's already there, and in the second he is the first senior person of authority called.
* BondOneLiner: "Keep the faith"
* BringIt: Strannix to Chief Ryback during their knife fight.
* CaptainObvious: Admiral Bates declaring "We gotta lot of trouble on that ship" when he's just finished talking with Ryback in the middle of a heated gunfight is certainly redundant.
* {{Chef of Iron}}: ''And how!'' Seagal's character is obviously not to be messed with.
* TheChosenZero: The main character, of course.
* CIAEvilFBIGood: While not the FBI, the dichotomy between CIA and Army staff when handling the crisis of each movie plays out the same. CIA liasons are always presented as self serving, irresponsible, short sighted, and responsible for the creation of the villains, and the Army as as an exasperated ReasonableAuthorityFigure that has to clean up after them with the help of Ryback.
* CutHimselfShaving: Commander Krill says he cut himself shaving as an explanation for Ryback slashing his face. It was a better story then saying that he put Ryback in the kitchen storage.
* DaChief: Averted by Admiral Bates in the first film. Upon finding out that Ryback has ignored his orders to avoid contact if possible and is busy trying to kill all the terrorists himself, the Admiral's response is thus:
-->'''Chief Ryback:''' I'm sorry, sir, you can court-martial me if I live, sir!
-->'''Admiral Bates:''' All right, Chief... you are hereby authorized to do whatever is necessary to regain control of that vessel. Because if I can't control you, I might as well at least ''support'' you!
* DarkenedBuildingShootout
* DefensiveFeintTrap
* DidntSeeThatComing: The reaction of the bad guys when they discover the cook just happens to be a highly trained and decorated SEAL. Krill even lampshades it with "how little I knew."
* DieHardOnAnX
** First movie: Boat!
** Second movie: Train!
* DistractedByTheSexy: Averted during a memorable sequence in which Erika Eleniak's character bursts out of a cake, topless. Although Ryback's attention is diverted, he's still in control of the situation and quickly takes charge.
* DoesntLikeGuns: Casey claims he doesn't like guns and so does Jordan, but both end up using firearms. Casey is generally more at home using knives.
** [[InformedAbility Doesn't stop him]] [[CrazyPrepared carrying a .45 with him at all times in the second film]].
* TheDragon: Krill in the first film, being Strannix's inside man and deputy across the operation
* DragonInChief: Implied in both films, with Krill in the first and Penn in the second successfully intimidating their employers with threats when the operaton is threatening to fall behind schedule.
* EveryoneKnowsMorse: In the first movie, Ryback is able to rescue a group of survivors trapped behind a welded-shut hatch who just happened to be broadcasting Morse code as he was nearby. Somewhat justified in that he was previously a Navy SEAL.
* EvilIsHammy: Creator/TommyLeeJones (Strannix) and Creator/GaryBusey (Krill) look like they're having an absolute blast in the first movie. Jones in particular is complete over the top villainous awesome.
* EyeScream: Ryback gouges out [[spoiler:Strannix's]] eye before killing him off.
* FingerInTheMail: Strannix recounts a tale of how he sent his CIA superior the fingers of two assassins who were sent to kill him.
* HiddenDepths
* InvincibleHero: A common complaint for the films is that, unlike Bruce Willis in ''Film/DieHard'', Seagal's Ryback disposes of everyone -- mooks, TheDragon, the BigBad -- without breaking a sweat or losing the cool facade, which tends to suck out some of the potential drama or excitement.
* IResembleThatRemark: As [[TheMole Commander Krill]] reads through his now-dead superior's report on him, he notices that he pegged Krill for being psychologically unstable. Krill, in drag, asks his associate if he looks like he needs psychological help.
* JumpingOutOfACake: At the beginning.
* KindaBusyHere: Casey Ryback is shooting it out with the hijackers when he gets a call from the ReasonableAuthorityFigure, and his female sidekick answers.
-->'''Admiral Bates:''' "I'm trying to get ahold of Ryback."
-->'''Jordan Tate:''' "He's in a gunfight. I'll have to take a message."
* LethalChef: Inverted and played with. Ryback is known in-universe as a great cook, but he still can kill you by other means.
* TheLoad: Jordan, although [[AdrenalineMakeover she shows]] ActionGirl [[AdrenalineMakeover potential]] in the last 20 minutes of the film
** She's also pretty GenreSavvy. He tells her to stay back "where it's safe". Her reply, "The safest place on this ship is three feet behind you!"
* {{MacGyvering}}: Ryback improvises explosives and other tools using a combination of everyday objects like paint thinner and military implements like gunpowder from a grenade.
* TheMole
* MotiveMisidentification: The Pentagon think Strannix has gone insane and is planning to just launch the ship's missiles at random thanks to his act. It takes Ryback's phone call for them to realize Strannix is quite sane and is planning to steal and sell the nuclear arsenal on the black market.
* MsFanservice: We are introduced to Erika Eleniak when she jumps out of a cake in a [[FetishFuel naval officer's uniform]] which she quickly strips off to reveal a great pair of tits.
* NeverBringAKnifeToAFistFight
* NoodleIncident: How and when Ryback and Strannix met previously.
* NotSoDifferent: Flipped around, from Seagal's protagonist to Jones' antagonist.
--> '''Ryback:''' "We're the same, you and I."
* ANuclearError
** Averted when it's stated that hitting nukes with high explosives won't set them off.
** Played straight when a self-destruct code transmitted to a cruise missile in flight causes it to blow up.
*** It should be noted, that the nuke didn't go nuclear, it just detonated its self destruct and fell from the sky.
* ObfuscatingInsanity: Strannix uses this when dealing with the brass monitoring the hijacking to misdirect them from his true motives.
* OhCrap: Seal Team 5 when faced with a heatseeker-wielding mook aiming at their helicopter. Ryback and his gang watching the same scene from too far away to assist.
** Also a couple of Strannix's men when they realize Ryback is a former SEAL.
* OurPresidentsAreDifferent: Subverted in that the real president at the time, [[UsefulNotes/GeorgeHWBush George H.W. Bush]], is shown sending the ship off before its final voyage, even if he's not involved in the bulk of the movie.
* PrettyLittleHeadshots: While there is some brutal violence, the headshots (most notably in the first film) are clean and leave small, relatively bloodless holes.
* PsychoSupporter
* ReasonableAuthorityFigure: Admiral Bates in 1 and 2.
* SentryGun: The Phalanx CIWS aboard the ''Missouri''.
* ShoutOut: Strannix and the submarine crew use names like "Roadrunner" and "Wile E. Coyote" as codenames, referencing the classic Warner Bros. cartoons. Guess which studio ''Under Siege'' is from.
* SpannerInTheWorks: The villains have carefully planned this entire thing out, prepared to take on everything from Navy reinforcements to rebellion among the crew...but never considered how the ''cook'' might just be the most capable warrior on the entire ship.
* StuffBlowingUp
* TookALevelInBadass: Jordan Tate changes from TheLoad to an ActionGirl when she pulls a BaitAndSwitchGunshot to save Ryback's life.
* VillainousBreakdown: Strannix goes completely insane after Krill is killed, and his eardrums burst due to the shockwave from the Missouri's 16" guns firing, including babbling about cartoon characters.
* VillainBall: Prior to the VillainousBreakdown both Strannix and Krill refuse to pick up the ball, with the worst decision being only sending a couple men to the kitchen at the start (which is understandable as they had no idea how dangerous Ryback was). After that, Strannix orders his men into roving patrols, reporting in regularly, not to pursue Ryback into unsecured areas, to immediately call for backup should anything happen, the sub has backup anti-air weapons used to take out the SEAL Team, Krill smartly figures that putting the crew in danger will create a situation where they can take out Ryback, and they notice Ryback trying to sabotage the submarine.