According to the Australian DVD sleeve notes, "Producer-Director Dick Powell let the public decide the ending for The Enemy Below. He filmed the movie with two endings, then let a preview audience vote for the ending they liked best. The ending he used won by unanimous vote." The ending which wasn't used had both submarine commanders, Captain Murrell (Robert Mitchum) and Von Stolberg (Curd Jürgens) die by drowning at the end of this picture when Murrell dives into the sea to rescue Von Stolberg. The used ending was the happy ending which had both of them rescued by a ship. Details of the two endings were reported in a July 1957 edition of 'The Hollywood Reporter' which stated that Powell filmed the two endings because he thought that the original ending (the unused one) was too bleak.
American movie debut for German actor Curd Jürgens.
Average Shot Length = ~8.7 seconds. Median Shot Length = ~6.3 seconds.
In an interview in July 1977 with 'The New York Times', German actor Curd Jürgens who played the German submarine commander Captain Von Stolberg in this movie said: "This was an important picture for me because it was the first film after the war in which a German officer was not interpreted as a freak."
In real life, the destroyer USS Borie (DD-215) rammed U-boat U-405 and was sunk. The Borie was severely damaged, could not be salvaged and sank the next day.
One of the final theatrically released movies of director Dick Powell who soon after worked exclusively in television.
One of the technical consultants working on this movie was Albert Beck, a former German U-Boat submarine sailor, who advised on the submarine scenes.
One of the two lead characters in this movie, the American captain John Murrell played by Robert Mitchum was an English captain in the D.A. Rayner novel 'The Enemy Below' that this film is based on.
Some of D.A. Rayner's wartime submarine adventures and experiences which appeared in his 'The Enemy Below' source novel to this movie and were adapted into this picture's story as well can be researched in Rayner's other book, 'Escort: the Battle of the Atlantic', particularly the 11 November 1944 Southern Ireland encounter between U-1200 and Allied corvettes (See pp. 224-228).
The American ship used in this movie was a Destroyer Escort by the name 'USS Whitehurst' (DE 634). My father was in the Navy at that time, and he helped paint over the 634 so the new number could be added. FYI, the 'USS Whitehurst' was sunk as a target for a new torpedo on 28 April 1971.
The destroyer escort 'USS Haynes' in this movie was played by the real 'USS Whitehurst' (DE-634). The cast spent about a month filming on board this vessel. Many of the crew of the 'USS Whitehurst' appeared in this movie. 20th Century-Fox production notes for this movie from the AMPAS Library declare that the 'USS Whitehurst' was a battle-hardened veteran from the Second World War which had during World War II been stationed at Pearl Harbor, Hawaii.
The finale rescue was shot on location in the sea at Long Beach, California and on the ship the 'USS Alfred E. Cunningham' (DD-752), an Allen M. Sumner-class destroyer. Other location filming sites included the Pacific Ocean near Oahu, Hawaii for scenes on the 'USS Whitehurst' portraying the 'USS Haynes'.
The name of the British vessel the 'HMS Hecate' from this movie's source novel 'The Enemy Below' by D.A. Rayner was changed for this film to the name the 'USS Haynes'.
The slogan in the U-boat (Führer befiehl wir folgen) translates as "Fuehrer lead, we follow you."
The television episode Balance of Terror was based almost entirely on this film whilst another TV episode Killers of the Deep was also based on this movie. The latter also used footage from this movie and also starred one of this movie's main cast, David Hedison.
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". As a more popular song, it's also known by the first line of lyrics: "So leben wir" (translation: "That's how we live").
The U-Boat seen in this movie is far roomier and spacious, clean and tidy than the real German U-boats of World War II (which were more realistically depicted in the later movie, Das Boot). During the Second World War, these u-boats did not have passageways and private rooms and were dirty and cramped.
The vessel the 'USS Whitehurst' was used in this movie and its captain, Lieutenant Commander Walter R. Smith USN acted as a technical advisor to the film production. Twentieth Century-Fox studio publicity stated that Smith played a role as this ship's Chief Engineer in the movie. Smith is not credited as such nor for any role and CBCS Credits state that Robert Boon portrayed a Chief Engineer in this movie. Apparently, Smith is the character who can be seen in the movie reading the comic 'Little Orphan Annie'.
This movie as based on the novel by D.A. Rayner and the book and it's dust-jacket can be seen at the beginning of one of this movie's trailers.
This movie represents one of a select group of a few World War II submarine movies which have won the one single Academy Award in a technical category, that's just only the one Oscar in either special effects or sound editing. These movies include Crash Dive; The Enemy Below; Torpedo Run and U-571. The non-WW II sub-movie, The Hunt for Red October also won just the one Oscar as did the WW 2 part sub-movie 49th Parallel, but for Best Original Story.