Continuity mistake: Tyler states he doesn't know what's going on to a few seamen and tells them to do their jobs. As the shot changes the seamen have all disappeared from the background. (00:14:50)
Continuity mistake: When Tyler is out on the deck, he has his hand raised. When the "boat secure" order is shouted it's now lowered and holding on to his glass. (00:12:10)
Factual error: When the German "destroyer" is attacking, it drops a steady stream of depth charges. I reality, depth charge attacks were made by locating the sub on sonar and dropping a pattern of five or ten charges at a time when the escort ship was above the target. These were set for the estimated depth and would have gone off at roughly the same time.
Plot hole: The Americans disguise S-33 as a German Type VII U-boat to pose as the German resupply boat. This is a pretty bad idea, since all resupply boats are of the Type IXV and not Type VII. Of course in a severe storm the differences between types might go unnoticed, but the plan could not rely on that alone. In good visibility, any able German watchman would be able to spot the difference quickly.
Plot hole: At the beginning of the movie, the German commander sends a radio transmission with the damaged sub's position at "AL 85-32." The German Kriegsmarine divided up the Atlantic in grid squares like these, but "AL 85-32" means the damaged sub is just roughly 375 miles west of Ireland, but more than 2700 miles from the US east coast. There is no way on earth the Americans beat the Germans to this location, especially since the German supply sub is already en route. Funny enough considering the controversy about the movie, for this position the British would have been in perfect position to intercept.
Factual error: At the beginning of the movie, the German commander wants to send an emergency message with coordinates to the BdU, the German Submarine Command, to send help. The scene is subtitled in English with "To Berlin: Location 85-32." However, the command post at the time was based in Lorient, France and not in Berlin. (00:08:05)
Suggested correction: He didn't send the message to the BdU, his message was send to the OKM (OberKommando der Marine), which had its headquarters in Berlin, because it involved the enigma code (although the movie is only loosely based on historic events). These kinds of messages were always send to Berlin. This is because the OKM answered to the OKH, which in turn answered to Hitler who was of course also in Berlin. This is their concern, not that of the BdU.
Of course he does, the commander literally says to the radioman "Ruf an BdU absetzen: Position AL 85-32. Alle Maschinen ausgefallen, manövrierunfähig, erwarten Hilfe" or "Send transmission to BdU: Position AL 85-32. All engines out of service, unable to manoeuvre, we expect help." This was correct procedure, proper chain of command would always be to contact the BdU, not the OKM. Also the integrity of the enigma was probably not a concern at that time, the crew would have ample time to destroy all sensitive materials if they were in danger. The German commander's main concern was to get his sub back up and running.
Right, I couldn't understand that part before. But you are right.
Deliberate mistake: In the scene near the end of the movie when Trigger is in the bilge trying to stop the air leak, the concussion of an artillery shell fired from the destroyer shakes some pipes loose. The mistake is that one of the flanges visible on a section of pipe has no bolt holes, making it impossible to join that pipe to anything.
Continuity mistake: After the German captain has attacked Tank and handcuffed him to the crane, the pattern of blood on Tank's face changes at least twice. First, he has two channels of blood running down the left side of his face under his nose and on his chin, and no blood on his lips or the right side of his face. Then, when Eddie and Tyler arrive, there is blood smeared all over Tank's nose and lips. Finally, after Tyler takes the cuff off and is yelling at Tank, all of a sudden there is a line of blood from Tank's nose across his cheek to his right ear. (01:09:05)
Other mistake: A German U-boat could dive in less than 30 seconds. By the time the boarding party even got to the conning tower the boat would already have been submerged.
Suggested correction: Just because it can, doesn't mean it has to. Not a mistake.
Yes mistake. The order to crash dive is heard. On a German sub the cry "Alarm!" always implied an order to crash dive as quickly as possible. A bit later the order to dive is given again. Practice on German subs was to open the quick-release vents as soon as the prompt "hatch latched" was given - in case of air attack often before that, meaning the vents were already open while crew members were still dropping through the hatch, resulting in the last guy getting an involuntary shower. True, the boat couldn't have dived in record time because they had no way in the ship, but still, at the very least the first thing the boarding party should have needed to do after taking the Central of U-571 should have been to close the vents and blow the tanks.
Continuity mistake: Just after Mazzola's been killed, Tyler unlocks the handcuffs from Tank. The handcuff starts swinging as soon as Tank pulls his hand free, but in the next shot it's stopped moving. (01:09:42)
Deliberate mistake: When the Americans are in the U-571 battling the resupply sub, Tank gets the engines running and starts the sub moving forward. There is an exterior shot of the sub's propellers, with the port prop turning counterclockwise and the starboard prop turning clockwise. Then Tyler wants to turn right to heading 010, and he orders "Starboard back full", which should reverse the direction of the starboard propeller to help turn the sub. Two exterior shots later, however, the props are shown still turning exactly the same way they were before Tank reversed the starboard engine. (00:52:00 - 00:53:35)
Continuity mistake: Mazzola has just been killed and when Tyler helps Tank, first he holds Tank using his left hand, then the next shot by his right.