Factual error: U-571 was sunk on January 8, 1944, by an Australian Sunderland. She was previously damaged by an Allied destroyer on March 22, 1943, but managed to come back to the base. All supply submarines (Type XIV or Type VIIF) were actually sunk by Allied planes or surface ships. I know that the movie is entertaining rather than historical, but why didn't the movie makers choose boats that disappeared without a trace instead?
Factual error: The submarine gets buzzed by a single engine German fighter. They are somewhere between the US coast and Greenland. The Germans had no aircraft carriers nor bases in the area. Since it was not a float plane how did the fighter get there? It could not possibly have flown the several thousand miles from continental Europe.
Factual error: At the beginning of the film the German commander is shown directing an attack using the periscope in the control room. German U-boats had two periscopes: a 'sky' scope (the one in the control room) used exclusively for searching the area directly above the boat prior to surfacing, and the 'attack' periscope located in the conning tower (turm). It was not possible for a German submarine commander to direct an attack from the control room periscope as depicted in the film.Badbird
Continuity mistake: Just after shooting the radio room on the German destroyer, U-571 submerges so quickly that the sailors do not manage to plug the gun. After a few moments when the boat goes from 180 to 200 meters there is a short shot from the above when we can clearly see that the gun is perfectly plugged. (01:13:30)
Factual error: When the marine commando shows the sailor his "luggage" (the boxes of explosives) to be loaded onto the submarine, some of the boxes have orange Explosive B placards. Those are Dept. of Transportation placards. The D.O.T. didn't exist until 1966 and the placards were not used until later than that. (00:19:55)
Continuity mistake: After the melee with the destroyer above the surface, they attempt to dive and travel under the keel of the destroyer to escape the deck guns. As the camera is going underwater, the destroyer can be seen, but when the camera is below the surface, its keel cannot be seen.Phil Watts
Factual error: Although the type of mission depicted in the movie did occur, it was not Americans that were known to do them. Canadian and British teams were specialized to do this mission.
Factual error: The German supply U-boat couldn't have sunk the S-33 with a torpedo, as neither the Type XIV nor any other class of German supply sub was equipped with torpedoes (this would have meant less storage space for cargo).
Factual error: When the boarding party are eating dinner on SS-33 before the raid, some of their spanking-new, freshly pressed Kriegsmarine utility uniforms (strange in itself) have breast eagles on the left chest instead of the right. I've never seen any German Wehrmacht uniform with an eagle on the left.
Continuity mistake: As the submarine is preparing to leave the dock in one of the movie's first scenes, Bill Paxton, the commander is standing on the top part of the sub. A seaman is walking in Bill Paxton's direction and the camera is at a distance. As the camera zooms in the man walking should have been in the frame under Mr. Paxton but he just disappeared. (00:20:20)
Continuity mistake: When the German destroyer is with U-571, look at the ship. Notice in the first shots there are 2 gun turrets on either side. Yet in the later shots during the final battle there's only one turret. In addition, right before the turrets are shown turning to fire, look at the ship again - they are already aimed at the U-boat. I guess the Germans felt the need to do this two times.