Based directly on the real commander of U-96 during Lothar-Günther Buchheim's patrol. The portrayal aligns well with accounts of Lehmann-Willenbrock's professionalism and demeanor.

Represents the author Lothar-Günther Buchheim, who served as a war correspondent aboard U-96. His experiences and perspective shift are central to the source material.

Based on the real Chief Engineer of U-96 during Buchheim's patrol, Hans Peter Rothe. The character accurately reflects the immense pressure and responsibility of the LI role.

Represents a type of officer found in the Kriegsmarine, though likely a composite character rather than based on a specific individual from the U-96 patrol.

Represents the younger, less experienced officers on U-boats, likely a composite or fictional character embodying common traits.

Represents the experienced non-commissioned officers vital to U-boat operations; likely a composite or fictional character, not based on a specific known individual.

The film is based on U-96's seventh patrol (codenamed "Feindfahrt") in late 1941, during which Lothar-Günther Buchheim was aboard.

The scenes accurately portray the tension, procedures, and dangers of U-boat attacks on Allied convoys during this period of the Battle of the Atlantic.

The harrowing storm sequence realistically depicts the extreme weather conditions U-boats faced and the physical toll on the crew.

U-boats relied on encrypted messages for orders, and the Enigma machine was central to German naval communications (though its eventual cracking was pivotal).

While specific details might be fictionalized, neutral ports like Vigo were known locations for clandestine support activities for German U-boats.

U-96 was indeed ordered to transit the heavily defended Strait of Gibraltar to enter the Mediterranean Sea in late November 1941.

U-96 was attacked by a British Fairey Swordfish aircraft on November 30, 1941, while attempting the passage and sustained significant damage.

The boat was heavily damaged and submerged, making emergency repairs on the seabed. However, the extreme depth shown (280m) is likely exaggerated for drama; the actual depth was less.

U-96 did manage to surface and return after the Gibraltar attack, but it returned to St. Nazaire, not La Rochelle as depicted in the film.

This ending is entirely fictional, created for dramatic impact. The real U-96 survived the Gibraltar incident, returned safely, and continued service; Lehmann-Willenbrock survived the war.

The film effectively portrays the long periods of inactivity, cramped conditions, and psychological strain that were hallmarks of U-boat service.

The film accurately shows the erosion of morale and the emergence of anti-establishment sentiment as the crew endures hardship and questions the war effort.

In late 1941, while dangerous, Allied anti-submarine warfare hadn't reached the overwhelming effectiveness it would achieve later in the war (e.g., post-mid-1943).

Highly acclaimed for accuracy, the cramped, complex, and claustrophobic set was meticulously recreated based on historical plans and museum examples, faithfully showing the sub's interior.

The film realistically portrays the lack of hygiene, constant dampness, poor air quality, pervasive smells, and extreme lack of personal space inherent to U-boat life.

The uniforms, including the iconic leather gear and variations in dress reflecting long patrols, accurately represent Kriegsmarine U-boat crew attire.

La Rochelle was a major U-boat base with protective pens, but U-96 was primarily based at St. Nazaire. The film uses La Rochelle effectively to represent such a facility.

Procedures for diving, surfacing, torpedo attacks, and damage control are depicted with a high degree of technical realism, reflecting actual U-boat operations.

The film captures the specific period well – U-boats were still effective but facing increasing danger, particularly from aircraft, reflecting the shifting tide of the battle.

The sound design, emphasizing creaking metal under pressure, sonar pings, engine noise, and depth charge explosions, significantly contributes to the realism and tension.