Until the Japanese attack on Pearl Harbor, the German U-boats had been ordered not to engage the United States in war like activities. However, with Japan’s declaration of war, Hitler no longer felt such measures were required and Germany declared war on the United States on December 11, 1941.
The first plan of attack of the Germans against the United States was called Paukenschlag, which means “Roll of the drum” or Operation Drumbeat. Paukenschlag, orchestrated by U-boat commander Dönitz, was to be a surprise and swift attack on the Eastern Sea coast of the Americas. Due to other military events few U-boats were available for the mission. Six German U-boats were initially available for the mission.
On Jan 12, 1942 the British Steamer Cyclops was sunk by German U-123, 300 miles off Cape Cod and so began the Paukenschlag. The SS Norness and the British tanker Coimbra were sunk off Cape Hatteras on January fourteenth and January fifteenth respectively. The killings continued and in all 13 vessels were sunk between New York and Hatteras in approximately 2 weeks.
Though technically the Paukenschlag ended on Feb 6, 1942, the U-boat attacks did not. German submarines continued to attack and sink Allied vessels all along the eastern seaboard. The Tanker, O.A. Knudsen was attacked off the coast of the Bahamas, three times in twelve hours. The tanker Gulftrade was sunk only two miles off Barnegat. The Tanker Tiger was torpedoed off Cape Henry, while trying to rescue a pilot. The Tolten, a Chilean freighter, was sunk only 30 miles off Ambrose Channel, New York.
It is believed that some of the success of the German attacks is due to their ability to interpret coded messages between the British and the US. Another aspect that led to the successful attacks against the US seacoast was United States citizens themselves. US coastal cities initially refused to darken their harbors, giving ample lighting to night time shores. This allowed U-boats to lie at periscope depth and launch torpedoes toward a vessel silhouetted by shore lights. Seamen were killed due to our own selfishness. Finally on April 18, 1942 waterfront lights were ordered out. The U-boat massacre on the eastern coast of the Americas continued until July 1942.