Produced and directed by Dick Powell, the film was based on the 1956 novel of the same name by Denys Rayner, a British naval officer involved in antisubmarine warfare throughout the Battle of the Atlantic.

Once a skilled game of cat-and-mouse tracking the U-boat gives way to a series of even more finely honed and intuitive attacks, the crew falls in strongly behind their new skipper.

Murrell is matching deadly wits with U-boat Kapitän zur See von Stolberg, a wily former World War I Unterseeboot skipper deep into a conflict he resents for a Nazi regime he detests.

As the battle that emerges tests both commanders and their crews, each man grows to respect his opponent as he discovers his rival can read his mind.

Murrell stalks the U-boat and subjects von Stolberg and his crew to hourly depth-charge attacks, trying to force him to surface where his ship is more vulnerable.

With his own vessel now foundering, von Stolberg orders his crew to set explosive scuttling charges and abandon ship, putting the Haynes in further peril.

Murrell, the last man aboard, is about to join his crew in the lifeboats when he spots von Stolberg standing on the conning tower of the U-boat.

Lieutenant Ware returns in the captain's gig with a mixed party of American and German sailors, who race up the cargo nets to save the last survivors before the tangled vessels go up together in a conflagration.

On 6 May 1944, USS Buckley, which was the lead ship of the same destroyer escort class portrayed in The Enemy Below, actually rammed and sank a U-boat in combat before capturing many of the German crew.

The tune sung by the U-boat crew on the ocean floor between depth-charge attacks is from an 18th-century march called "Der Dessauer Marsch," known by the first line of lyrics as "So leben wir" ("That's how we live").