During the Second World War, the Atlantic Ocean proved to be a key strategic hub for supplies being sent from the United States to Nazi-besieged England via numerous supply convoys. The Nazis, aware of the importance of these supplies for the survival of the island, began a ruthless submarine warfare through the use of fearsome U-boats, with the objective of sinking as many supply ships as possible. At the head of the German submarine fleet, which numbered more than 1,000 submarines during the course of the war, Admiral Karl Donitz was appointed, a proponent of the ''Wolfpack'' tactic, which can be translated as ''pack of wolves''.

Donitz had been commander of submarines during the Great War and had realised the frailties of operating single submarines against large escorted convoys, a change of approach was needed. The admiral's new strategic proposal was that of a ''pack'' action of the U-boats, which, like a pack of wolves, would work together in attack groups to overwhelm the enemy, even if they were numerous.

In 1940 and 1941 alone, this successful tactic allowed the Germans to sink hundreds of Allied ships causing thousands of casualties. Despite this initial success, the Allied response was not long in coming and the turning point came with the introduction of sonar technology. Sonar allowed Allied ships to detect submarines underwater and entire groups of Allied naval patrol vessels began to actively hunt down German U-boats, causing heavy losses to the submarine fleet. In May 1943 alone, some 41 German submarines were sunk by Allied patrol boats, marking the beginning of the decline of the German fleet in the Atlantic. By the end of the war, Germany had lost nearly 700 U-boats and some 30,000 submariners, swallowed by the Atlantic Ocean. This battle demonstrated how technological as well as tactical advancement had become and still is one of the key elements in determining the outcome of wars.