Factual error: Unless the USS Logan's captain had been previously seconded to Bletchley Park, he would not be cognizant of the Enigma cypher machine, yet he instructs the chief to secure the one in the U-boat.
Factual error: The German captain and XO are playing chess and discussing the sinking of the American cruiser. They had been subjected to severe depth-charging earlier, but no American cruiser carried ASW munitions.
Factual error: During an emergency dive drill on the Swordfish, a bowl of dishes is dropped, causing the sonar operator to wince in pain. Unless the transducer was relocated to the interior of the sub, or the operator had overly sensitive hearing, it would not have impacted him so severely.
Factual error: The vessel sunk by the U-Boat is not an American destroyer or destroyer escort, it was actually a British or Canadian corvette.
Factual error: The opening scene shows Lieutenant Commander Sullivan being interviewed by a Rear Admiral at CINCPAC, according to the signage. He would never be assigned to a submarine scheduled to be deployed to the Atlantic.
