Brutal Fate of German U-Boat Crews During World War II
During the tumultuous years of World War II, the German U-boat crews faced a unique and harrowing kind of warfare—one that was silent, claustrophobic, and deadly. I have spent considerable time exploring their stories, and in this article, I want to take you deep beneath the ocean’s surface to understand what life was truly like for these men. Drawing on firsthand accounts and detailed historical research, I will walk you through the brutal training, the deadly missions, the fleeting moments of glory, and the ultimate tragic decline of the U-boat force. This narrative is inspired by the incredible work of The Soldier’s Diary CZ, who masterfully documented these experiences.
⚓ The Harsh Reality of Life Inside a U-Boat
Imagine being sealed inside a steel coffin miles beneath the ocean, where the air smells of old sweat, burnt oil, and stale bread. The sun hasn’t been seen for weeks, and the only company you have are your comrades, crushed together in tight quarters with weapons that decide life or death. This was the brutal reality of the German U-boat crews.
Every launch of a torpedo was accompanied by a silent, tense ritual. The hiss of compressed air, the vibration of the submarine’s hull as it seemed to breathe, and then the deadly silence as the torpedo sped into the darkness. Outside, the enemy was unaware of their presence, but inside, every man felt the heavy weight of the ocean’s pressure and the looming threat of death.
The crews were young—mostly under 25—but they carried an intimidating reputation. British propaganda called them the “Grey Wolves,” while within their ranks, they considered themselves the elite of the new German Navy. Out of 40,000 sailors who served in the U-boat fleet, an astonishing 30,000 never returned alive. This mortality rate was unmatched in any other German military service during the war.
Despite this, those who survived shared a common memory: they joined because the U-boat force was the toughest unit of all. Surviving meant you were among the best, a sentiment expressed by a veteran whose voice, even decades later, was thick with pride and horror.
🛠️ The Brutal Training and Brotherhood of the U-Boat Crews
The story of these submariners began long before their first patrol. Secret engineering projects were underway in places like The Hague and Finnish shipyards, disguised under commercial covers to evade treaty restrictions. When Hitler rose to power in 1933, these covert efforts were formalized into a rigorous training school in Kiel, Württemberg.
Here, 80 candidates and eight officers formed the first crews, undergoing intense training that shaped them into a tightly knit brotherhood. The training was brutal. Simulators mounted on old minesweepers mimicked rudders and periscopes, sending trainees through day and night drills in the Baltic Sea, with orders to fire practice torpedoes at any moving target.
One veteran, Matrose Nobergefray Hans, recalled his arrival at the shipyard with a sense of adventure but also the immense pressure to master every valve and mechanism before he turned 20. This painstaking education forged near-blind trust between leadership and crew, essential for survival in the unforgiving depths.
The U-boats themselves were divided into two main types: the coastal Type II, carrying about 25 men, and the ocean-going Type IX, with crews of 56. The organizational structure split into two branches—sailors and technicians—led by a commander, two watch officers, and a chief engineer, with specialists like radiomen, torpedo operators, helmsmen, and diesel and electric stokers below deck.
Space was at a premium. Every man knew his bunk could disappear overnight if new torpedoes or supplies were loaded. To boost morale, crews painted emblems on their conning towers—raging bulls, laughing saw blades, devils with pistols—while swastikas were surprisingly rare, appearing on only 14 vessels. These symbols, often linked to hometowns or personal mascots, also adorned uniforms in the form of handmade badges and knitted sweaters.
Their camaraderie was strengthened by rituals: surviving the first sinking, sharing rum tea after confirming an explosion, signing the ship’s log before returning to port, and using nicknames that replaced rank. Despite the rigid hierarchy, inside the tower, all were equals—brothers in the same deadly club.
🌊 Early War Patrols: The Thrill of the Hunt
The war’s outbreak in September 1939 marked the beginning of a new chapter. The infamous sinking of the passenger ship Athenia by U-30 was a grim start, planting the image of the U-boat sailor as a shadowy assassin in public consciousness. Early battles had one key advantage: surprise. Convoys were not yet standard, escort systems were makeshift, and many Allied ships sailed unprotected along predictable routes.
For U-boat commanders, this was a time of opportunity. Each patrol was a gamble with fate, a chance to inflict maximum damage. Their tactics were straightforward but effective: night surface navigation, daytime periscope searches, and sudden, close-range torpedo attacks.
Many crewmen faced their first real combat missions, where fear, concentration, and silence were constant companions. Inside the control room, after every hydrophone ping, a tense hush fell as they listened for the telltale sound of propellers. When a target was identified, the crew moved with precise choreography—calculating course, loading tubes, setting gyroscopes, and waiting for the order to fire.
Yet torpedoes were unreliable. Premature detonations and erratic trajectories were common. Magnetic detonators were especially problematic, often failing to explode near the target, frustrating commanders who sometimes resorted to firing from dangerously close distances to guarantee hits.
At this stage, U-boats still operated mostly on the surface, relying on diesel engines for speed and endurance. Life on board was a mix of routine and tension: officers drank hot coffee in the navigation room, sailors slept amid potatoes, hanging hams, and oily steel cylinders in the torpedo room. Sightings of smoke on the horizon triggered a flurry of activity to approach, identify, and plan attacks.
Some attacks ended swiftly with a single well-placed torpedo, while others involved surface gunfire after the crew abandoned ship. The image of the U-boat sailor offering blankets and cigars to survivors contrasted sharply with the brutal reality of the war beneath the waves.
🎯 The Golden Age: U-Boats Dominate the Atlantic
The occupation of France in June 1940 transformed the U-boat war dramatically. No longer forced to undertake exhausting and perilous journeys around the British Isles, submarines now had access to Atlantic ports like Bordeaux, Lorient, Brest, La Pallice, and Saint-Nazaire. These became wolf dens from which they could strike directly at the heart of Allied shipping lanes.
This period, later called the “Happy Time” by the crews themselves, was marked by shorter transit distances, increased patrol frequency, and abundant torpedoes and fuel. Heinrich Class, a torpedo operator on U-99, recalled the exhilaration of setting out from Lorient and seeing their first merchant ship within 48 hours—a feeling as if the entire Atlantic leaned towards them.
During these months, U-boats seemed omnipresent. Convoys were inconsistent, air cover was minimal, and escort systems were still developing. Commanders like Karl Friedrich Marten boasted of sinking seven ships in just eleven days, with nights so long and seas so calm it felt like a perpetual hunt illuminated by burning wrecks.
Back on land, U-boat crews were hailed as heroes. French ports buzzed with excitement, officers received invitations to dinners and dances, and the war seemed confined to the sea. The contrast between the deadly ocean and the festive shore gave rise to a strange duality—death and danger below, wine and women above.
On board, the atmosphere was one of growing confidence. Commanders allowed longer sleep shifts, permitted shaving, and even prepared warm stews when weather permitted. “We weren’t afraid,” said a sonar operator from U-96. “We knew the enemy couldn’t touch us—yet.”
🔥 The Rise of the Aces: Legends of the U-Boat Fleet
In the early months of the war, sinking 40,000 tons of shipping was the benchmark for becoming an ace—a feat only a handful of commanders achieved by mid-1940. These men’s names began to circulate in official reports and public broadcasts, becoming symbols of skill, determination, and deadly precision.
Günther Prien of U-47 was among the first and most famous. His daring infiltration into the British naval base at Scapa Flow and sinking of the battleship Royal Oak catapulted him to legendary status. Charismatic and disciplined, Prien’s successes were celebrated with postcards and songs. He died in battle in 1941, leaving behind a fading but enduring legend.
Otto Kretschmer, commander of U-99, was equally renowned—not for flamboyance but for efficiency. Preferring night surface attacks from close range, he ensured every torpedo counted. Kretschmer amassed the highest tonnage sunk during the war and survived captivity, serving as a model of professionalism.
Joachim Schepke, known for his extroverted personality and magnetic presence, was also a notable ace before his death in 1941 at just 28 years old. Together, these commanders embodied the ideal U-boat leader: technically flawless, calm under pressure, and fiercely committed to their crews.
As France’s Atlantic bases opened, the scale of operations expanded dramatically. The 40,000-ton threshold for aces was raised to 100,000 tons or more, creating an elite within the elite. Commanders like Erich Topp and Heinrich Liebe joined the ranks, with Topp’s U-552 famously bearing a red devil emblem, sinking over 150,000 tons of shipping.
These men were young, often under 30, forged in the austere post-World War I period and trained in secrecy. For their crews, they were almost father figures; for the German public, symbols of dominance and hope.
☠️ The Turning Tide: Allied Advances and the Decline of the U-Boats
But the tide of war is relentless. By 1943, the ocean was no longer a sanctuary. Allied forces had learned from early losses, bolstered convoy defenses, and deployed advanced aircraft equipped with radar and powerful depth charges. The once-dominant U-boats became vulnerable targets.
Air patrols from bases in Iceland, Morocco, and Trinidad relentlessly hunted submarines. Technologies like centimetric radar, Leigh Lights, and Ultra intelligence cracked German codes, turning the Atlantic into a deadly trap. Every time a U-boat surfaced to recharge batteries, it risked instant detection and destruction.
One harrowing account from a crewman on U-1664 described being spotted by an American plane while surfaced, barely having seconds before a devastating attack. Only seven men survived that encounter. The Bay of Biscay, once a gateway to the Atlantic, became a graveyard as U-boats were bombed within sight of their home ports.
Losses mounted. In 1943 alone, over 250 submarines were destroyed, many on their maiden patrols. Experienced commanders were killed or captured, leaving inexperienced crews to face an increasingly hostile environment. One officer lamented that some of his men couldn’t even swim or read the 25-day format on navigation charts.
Morale plummeted. The air inside the submarines grew acidic and humid, causing respiratory problems and nervous breakdowns. The introduction of snorkels allowed longer submerged travel but brought new challenges—constant condensation, fatigue, and claustrophobia.
Attacks became desperate gambits rather than coordinated strikes. Some U-boats fired torpedoes blindly at shadows; others sacrificed everything for a chance to breach convoy defenses. Survivors returned to bombed-out bases, greeted by destruction and the loss of friends. The myth of the silent, invincible wolf was fading into ghostly shadows.
❄️ Arctic Convoys: The Frozen Frontline
Another brutal theater was the Arctic, where U-boats patrolled icy seas to intercept convoys supplying the Soviet Union. Here, the enemy was not just the Allies but the merciless cold. Submariners faced frostbite, freezing equipment, and the constant threat of being trapped beneath shifting ice.
Temperatures inside the hulls plummeted; metal surfaces wept with condensation, and periscopes fogged within seconds. Watch shifts on deck lasted only 15 minutes due to the biting cold. Men suffered frostbitten eyebrows and cracked lips but remained silent, their spirits numbed by the relentless environment.
Attacks were rare but deadly. Torpedoes often malfunctioned in freezing waters, and submarines risked being trapped under ice after an assault. One U-boat found itself caught between ice floes, unable to move, surrounded by the eerie creaks of the frozen sea. Only one of its crew survived when the vessel was eventually destroyed.
Returning from Arctic patrols was no relief. Crews arrived gaunt, haunted, and broken. The cold had aged them far beyond their years. The harshness of this front was a punishment and a grim initiation into despair. Unlike the relatively glamorous Atlantic battles, the Arctic war was a slow, silent death.
⚰️ The Final Years: Desperation and Decline
By 1944, the U-boat war was no longer a fight for victory but a sentence to slow death. The once-proud crews returned hollowed out, their numbers dwindling, their faith shattered. Every patrol was a near-certain death march.
New submarines, like the revolutionary Type XXI, arrived too late. Designed for extended underwater endurance with advanced batteries and silent propulsion, these vessels promised a turnaround. But only a handful ever saw combat, often with inexperienced crews and untested systems.
One Type XXI submarine, under Lieutenant Kašný, set out on April 30, 1945—the day Hitler died—but received orders not to engage and to return to port. Many others were scuttled by their own crews, their valves opened to sink them before capture. These were steel coffins without occupants, monuments to failure and futility.
The final days were marked by chaos and resignation. Bases in France were gone, communications were erratic, and orders contradictory. Some commanders dreamed of one last attack; others sought escape. Many simply waited in silence, unsure if the world above still waged war or had forgotten them.
Some submariners chose death over surrender, drowning themselves or committing suicide aboard their vessels. Others surfaced to surrender, blank-faced and broken, as enemy flags rose over their former strongholds.
The formal surrender came in waves, with many boats scuttled even after the war’s end. Survivors faced imprisonment, interrogation, and years of stigma. Their stories were buried under the collective guilt of a defeated regime, but for those who lived through it, the war ended long before the official ceasefire—often in 1943 or 1944, when hope died beneath the waves.
🌊 Reflections on a Forgotten War Beneath the Waves
The saga of the German U-boat crews during World War II is a story of extremes—of youth pressed into the tightest steel confines, facing the merciless ocean and the deadly hunter-killer tactics of their enemies. It’s a tale of brotherhood forged in darkness, moments of triumph overshadowed by overwhelming loss, and the slow, grinding erosion of spirit and machine.
These men were not just soldiers; they were shadows beneath the waves, their lives dictated by the rhythm of sonar pings and the silence of the deep. Their legacy is a testament to human endurance and the tragic cost of war fought in the most unforgiving environment imaginable.
Thanks to dedicated historians and storytellers like The Soldier’s Diary CZ, these voices echo across time, reminding us of the brutal fate endured by those who sailed the steel wolves of the Atlantic and beyond.
