Even though the number of U-boats on patrol was cut in half in October as ships returned to port to rearm and refuel, more were sunk the next month. U-48 sank HMS Royal Oak inside the supposedly submarine-proof home anchorage in Scapa Flow on October 14, 1939. Throughout the end of 1939, more ships were being sunk then were being built.
Things would only get worse the British. Churchill reported to Parliament in 1940 that 20 ships with 120,000 tons of food and fuel oil had to dock every day in order for Britain to hold out and win the war. But as the fortunes of France soured, so did the fortunes of the merchant marine supplying England with arms and materiel.
The fall of France on June 22, 1940 allowed the Germans to base U-boats closer to the Atlantic. The first one arrived on July 7, 1940. Dönitz put his “Wolf Pack” tactic he developed in the 1930’s into operation. With forward bases hardened against air attack in Loríent, France, several U-boats could track and attack convoys, stretching the Allies’ already hard-pressed escorts with simultaneous attacks.
The only other thing in the Allies’ favor, besides their enemies’ faulty torpedoes, was the lack of serviceable U-boats. In February 1941 Dönitz could only send twenty-two submarines into the Atlantic, with 30% on patrol at any given time.
The convoy system and long-range aircraft cut down on losses near land, but in the “mid-Atlantic gap” where long-range aircraft could not reach, the U-boats concentrated their attacks.
The United States Navy was actively engaged before the German declaration of war in December 1941. USS Reuben James was sunk on October 31, 1941 by U-562. This angered many “America Firsters” who thought this would bring the United States closer to the European war.
Actually the first aggression came from the Japanese. When the Germans followed suit on December 11, 1941, a second “happy time” would lie off the shores of the United States. The worst naval defeat in United States history, one overlooked by history and overshadowed by the losses at Pearl Harbor, would crash into the unprepared American merchant marine in the form of German torpedoes. Dead American sailors began to wash up on the American coastline, and civilians watched nightly as tankers and cargo ships burned in the night offshore. War had come to America.