A German submarine is boarded by disguised American submariners trying to capture their Enigma cipher machine.

Chief Klough: Well, Mister Tyler, if you ever need a chief, I'll go to sea with you anytime.
Ens. Keith Larson, Chief Torpedoman: They wouldn't give me five minutes to consumate my marriage. Five minutes!
Chief Klough: You're the skipper now. And the skipper always knows what to do whether he does or not.
Lieutenant Andrew Tyler: His body is gonna to save our lives.
Chief Klough: Those Krauts sure know how to build a boat.
Lt. Commander Mike Dahlgren: Relax gentlemen. She's old... but she'll hold.
Lieutenant Andrew Tyler: What the hell are you doing, huh? This is NOT a God damn democracy!
Marine Maj. Coonan: How deep does this thing go?
Lt. Commander Mike Dahlgren: Oh, she'll go all the way to the bottom if we don't stop her.
Lt. Commander Mike Dahlgren: You're a first rate X.O., Andy. A damn good submariner. I know the men like you.
Lieutenant Andrew Tyler: I'd give my life for any one of them, sir.
Lt. Commander Mike Dahlgren: I know you would. I'm not questioning your bravery. The question is: what about their lives? You and Mr. Emmett are good friends. You went to the Academy together. Would you be willing to sacrifice his life? Or what about some of the younger enlisted men? I know a lot of those guys look up to you like a big brother. You willing to lay their lives on the line?
[Tyler hesitates to speak]
Lt. Commander Mike Dahlgren: You see? you hesitate. But as a captain, you can't. You have to act. If you don't, you put the entire crew at risk. Now that's the job. It's not a science. You have to be able to make hard decisions based on imperfect information. Asking men to carry out orders that may result in their deaths. And if you're wrong, you suffer the consequences. If you're not prepared to make those decisions, without pause, without reflection, then you've got no business being a submarine captain.
Lieutenant Andrew Tyler: I didn't get my boat.
Lt. Commander Mike Dahlgren: I know.
Lieutenant Andrew Tyler: And with all due respect, sir, there's only one way that could've happened and that's if you withheld your recomendation.
Lt. Commander Mike Dahlgren: That's right. I just don't think your ready.
Lieutenant Andrew Tyler: What do you mean I'm not ready? Sir, I have worked my tail off on the S-33. I'm qualified in every area and then some. What executive officer has higher marks then I do, Captain?
Lt. Commander Mike Dahlgren: Andy! Your just not ready to take on a command of your own.
Seaman Bill Wentz, Radioman: Mister Tyler, please... don't tell the other guys I'm half German. They'll hate me.
Lieutenant Andrew Tyler: Yeah, sure thing, Wentz.
Lieutenant Andrew Tyler: Who's the boarding party?
Marine Maj. Coonan: Well, since you're the XO, you sir. Mr. Emmett, Mr. Larson, Mr. Hirsh and nine of your ships company. Captain, of course, will remain onboard the S-33.
Lieutenant Andrew Tyler: Mister, our boys are submarine sailors, not combat marines.
Marine Maj. Coonan: Boys onboard that U-boat are sailors, too. Your men will be ready, Lieutenant. I'll train them myself.
[During a depth charge attack]
Lieutenant Andrew Tyler: Mister Hirsch, step away from that bulkhead. The shockwave from one of these explosions could snap your spine.
Lt. Hirsch: Mr. Tyler.
Lieutenant Andrew Tyler: Yeah.
Lt. Hirsch: If you can't take out that destroyer, the danger is not that some of us may die. It's that some of us may live. These men have seen and heard things that must not be revealed to the enemy - our secrets, such as our radar capabilities, and our understanding of German encryption. If we fall into German hands alive, we will be tortured without mercy. Either you succeed in sinking that ship, or you see to it that none of us survive to be captured.
Eddie: It's the first time you ever seen a black man ain't it... get used to it.
Chief Klough: What the hell are those yardbirds doing to my boat?
[as depth charges start falling]
Seaman Ronald 'Rabbit' Parker, Torpedoman: Chief, you ever been depth-charged?
Chief Klough: Once, off Murmansk, back in World War One. One charge came so close, it rattled four teeth out of the skipper's head.
[a charge goes off overhead with a loud bang]
Chief Klough: Wasn't even close.
Lt. Hirsch: Last night at 0300 hours a British destroyer reported depth charging and sinking a German U-boat. However, sometime thereafter, Allied direction finding station triangulated a coded enemy radio signal to this position here near the chop line.
[indicates position on map]
Lt. Hirsch: We believe the U-boat was disabled, not sunk, and is drifting eastward on a four-knot current. Now, French resistance reported a resupply submarine sailed from the Lorient U-boat pens yesterday afternoon with engine parts and mechanics. Now, we believe it's gonna rendezvous with the disabled U-boat. On board that U-boat is this.
[picture of typewriter Enigma]
Ens. Keith Larson, Chief Torpedoman: A typewriter?
Lt. Hirsch: An Enigma code machine. It allows the German navy to communicate with it's submarines in secret, and our inability to decipher their messages is costing us this war. Mr. Coonan?
Marine Maj. Coonan: All right. This is basically a Trojan Horse operation. The S-33 will rendezvous with the U-boat, posing as the German resupply sub. I will lead a boarding party dressed in Kriegsmarine uniforms to the enemy submarine. We will take it by force and secure the Enigma. Any German survivors will be transferred to the S-33 and the U-boat will be scuttled.
Lt. Hirsch: The German resupply submarine will arrive at the rendezvous and will assume that the U-boat succumbed to its wounds and sank. The Germans must never suspect we have the Enigma. That is vital.
Lt. Pete Emmett: So it's a race?
Lt. Hirsch: Yes, effectively.
Lieutenant Andrew Tyler: Who's the boarding party?
Marine Maj. Coonan: Well, since you're the X.O., you sir. Mr. Emmett, Mr. Larson, Mr. Hirsch and nine of your ship's company. The captain, of course, will remain onboard the S-33.
Lieutenant Andrew Tyler: Mr. Coonan, our boys are submarine sailors, not combat marines.
Marine Maj. Coonan: The boys onboard that U-boat are sailors too. Your men'll be ready, Lieutenant. I'll train them myself.
Lt. Commander Mike Dahlgren: You've come to the right boat.
Lieutenant Andrew Tyler: [whispering] Tank, you alive back there?
Seaman Charles 'Tank' Clemens: Yes, sir.
Lieutenant Andrew Tyler: Good. Port ahead two-thirds.
Seaman Charles 'Tank' Clemens: Port ahead two-thirds. Aye, sir.
Lieutenant Andrew Tyler: [pulls out paper] Tank... can you fix the stern tube?
Seaman Charles 'Tank' Clemens: I don't know, Mr. Tyler.
Lieutenant Andrew Tyler: I don't want an "I don't know." Can you fix the torpedo tube? Yes... or no?
Seaman Charles 'Tank' Clemens: Yes, sir. I think I can.
Lieutenant Andrew Tyler: Thank you, Tank. Chief, make depth 1-6-0 meters.
Chief Klough: That's more than five hundred feet.
Lieutenant Andrew Tyler: Take us down, Chief.
Chief Klough: Aye, sir. One-six-zero meters. Twenty degrees dive both planes.
Eddie, Seaman Ronald 'Rabbit' Parker, Torpedoman: Twenty degrees dive, aye, sir.
Eddie: Mr. Tyler, sir, uh, do you plan on going up against a destroyer with only one fish in the tube and busted motor?
Lieutenant Andrew Tyler: Yes, I am, Eddie.
Lt. Hirsch: How wise is that, Lieutenant?
Lieutenant Andrew Tyler: Not very. But have a look. Chief.
[while speaking, drawing and showing Chief and Hirsch plan on paper]
Lieutenant Andrew Tyler: There is no way a two-knot submarine can get in firing position against a thirty-knot destroyer unless we go deep. At one hundred sixty meters, we can shoot out a bunch of junk from the forward tubes. It will resurface and create a debris field. Now the destroyer's going to go to the center of that debris field, shut off its engines to make it real nice and quiet and do an acoustic search to make sure we're dead. But we're not. See, we're here, on our way up to periscope depth. All right, principle of ascent velocity. We let our positive buoyancy pull us up and away from the destroyer. And when we surface we'll be showing it our ass at seven hundred yards. That is a pefect setup for a stern shot on a stationary target. Boom. It don't get much prettier than that.
Chief Klough: All right, Mr. Tyler. Passing 1-3-0 meters.
Lieutenant Andrew Tyler: Very well. Rabbit, I need you to load Mazzola's body into tube three and put an escape jacket on him to make sure he floats.
Seaman Ronald 'Rabbit' Parker, Torpedoman: Wanna shoot him out like garbage?
Lieutenant Andrew Tyler: [pause; slowly turns around] His body is gonna save our lives.
Seaman Ronald 'Rabbit' Parker, Torpedoman: I'll say a few words for him.
Lt. Commander Mike Dahlgren: If this thing goes south I will blow that Nazi boat right out of the water.
Seaman Anthony Mazzola: [reminiscing about a date] Anyway, I can see I'm not gettin' anywhere with her. So what I do is, I use my secret weapon. I tell her about the S-26. Does the trick right away.
Eddie: Now, you don't wanna be talkin' about that while we're underway!
Seaman Ted 'Trigger' Fitzgerald: Why, what happened to the S-26?
Seaman Charles 'Tank' Clemens: Yeah, what happened?
Seaman Anthony Mazzola: You guys don't know?
Seaman Ted 'Trigger' Fitzgerald, Seaman Charles 'Tank' Clemens: No.
Seaman Anthony Mazzola: [taking an egg from Eddie's tray] She was runnin' a test dive down off Norfolk. Shaft seal failed, and she sunk to 400 feet. Know how much water pressure there is that deep?
[Crushes the egg with one hand; Rabbit flinches]
Eddie: Mazzola, you wanna be the first one to eat powdered eggs on this cruise? Keep it up, man.
Lieutenant Andrew Tyler: He torpedoed me, Chief. Nine months aboard the S-33 doing the best job I know how. Doing everything once, and then doing it again just to make sure I didn't miss anything the first time.
Chief Klough: You'll get your chance sir. There's other commands in the navy.
Mrs. Dahlgren: Where's your date, Andy? It's not like you to arrive stagged like this.
Lieutenant Andrew Tyler: I'm afraid I couldn't get one on such short notice ma'am.