Audio problem: When the U-boat captain is called onto deck,he orders his machine gunner to fire at the sailors who are rowing towards them. As soon as he fires the ammo belt gets used up straight away, however the sound of the gun carries on for a short while longer.

Continuity: At the very beginning U571 is being depth charged and forced to surface but the attacking destroyer has disappeared.

Continuity: 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.

Factual error: At the beginning of the film the depth charge attack is shown rupturing a diesel fuel line in the engine room, which showers the fuel DOWN on the crew stationed there. In fact the fuel lines ran UNDER the deck plates and so a broken line could not shower fuel in that manner.

Continuity: 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.

Revealing: When the German destroyer is hit by the torpedo at the end of the film it is seen to stop dead in the water upon the torpedo impact. In reality momentum would have carried the ship forward some distance after the explosion. A thousand or so tons of steel just does not stop on a dime unless it hits something like a mountainside.

Continuity: When Mazzola dies, his eyes are initially open. The German captain pushes him away, and just before Mazzola's face goes out of camera he closes his eyes. In the next shot of him lying on his back on the floor, his eyes are open again.

Revealing: The German destroyer is actually an old converted minesweeper.