The Atlantic Ocean, vast and unforgiving, became the theatre of a deadly game of survival during the Second World War. As the war erupted in 1939, the waters between Europe and North America turned into a perilous battlefield, where the lifeline of nations was at constant risk. The Battle of the Atlantic, a relentless struggle for control over the vital shipping lanes, would soon become the longest and most gruelling campaign of the war.
At the heart of this conflict was the U-boat—a weapon of stealth and precision, Germany's answer to Britain's dependence on transatlantic trade. The U-boats prowled beneath the waves, their silent menace striking fear into the hearts of Allied sailors. British Prime Minister Winston Churchill would later reflect on this perilous time, admitting, "The only thing that really frightened me during the war was the U-boat peril." It was a peril that threatened to sever the lifeline that kept Britain supplied with the war materials and food it desperately needed to survive.
Admiral King recognized the critical nature of the U-boat threat to American supply lines during the early stages of U.S. involvement in the war. He said:
"The war against the U-boats is the most important battle of the war, which must be won before the war can be won." Roosevelt described German U-boats as "the vultures of the sea" and expressed grave concern over their attacks on American and Allied ships.
In response, the British resurrected a strategy from the previous war—convoying. In September 1939, they began organising merchant ships into protected groups, hoping to shield them from the lurking predators beneath the waves. But the early years of the war proved difficult. The U-boats adapted, launching their attacks under the cover of night, surfacing silently to strike at the convoys like wolves in the dark. Though initially met with mixed success, the Germans soon refined their tactics, and with the fall of France in 1940, the U-boats gained access to new bases along the Atlantic coast. From these strongholds in France and Norway, they could strike deeper and more effectively into Allied shipping lanes. The numbers alone tell a grim tale: around 3,000 vessels, mostly merchant ships, were sunk by these maritime predators. More than 5,000 seamen and passengers lost their lives in the icy waters. The death toll from U-boat attacks was staggering, surpassing even the tragic losses at Pearl Harbor.
The North Atlantic convoy routes faced relentless U-boat attacks, which led to the loss of 310,000 tons of shipping in just one four-week period during the fall of 1940. By the spring of 1941, Allied losses had escalated, with 142 vessels—totaling 815,000 tons—sunk over the course of two months. In a span of a year and a half, U-boat warfare had destroyed more than 700 ships, amounting to 3.4 million tons in total losses for the Allies. Churchill later recalled this grim time for England, noting, "The pressure grew increasingly, and our shipping losses were fearfully above our construction... Meanwhile, the new 'wolf-pack' tactics... were rigorously applied by the formidable Prien and other top U-boat commanders."
It was during this time that the U-boat crews experienced what they would later call "die glückliche Zeit"—the First Happy Time. For a time, the Atlantic seemed to belong to the predators, a playground for the hunter and a graveyard for the hunted.
Predator in the Atlantic follows one such U-boat and its crew, led by Captain Müller. In the cold, dark waters of the Atlantic, they face not only enemy fire but the weight of their own humanity.