America's Undeclared Atlantic War
Larson, George A., Sea Classics
Months before the infamous attack on Pearl Harbor the United States did little to hide that, though technically a neutral, its sympathies lay with France and Great Britain. Nowhere was this commitment better demonstrated than on the embattled Atlantic where American warships did their best to thwart Hitler's U-boats and sea raiders.
The US Navy was an active participant in the "Battle of the Atlantic" two years before entering World War Two. While the United States followed a policy of neutrality toward the European war, in reality, it was far from this objective. Germany's plan to erase its World War One defeat at sea to Allied naval power was began in 1938, referred to as "Plan Z.' The plan called for 300 ocean-going Unterseebootens (U-boats) by the estimated time of a probable war against England (hopefully not earlier than 1944).
German U-boats operational on 1 September 1939, were similar to those which prowled the North Atlantic during WWI. Although they had greater range and better equipment, their underwater speed and endurance remained about the same. U-boats developed later in the war were superior (Type-XXI), but did not reach combat in time or sufficient numbers to effect the outcome of the war at sea.
Unfortunately for the German Navy, on 1 September 1939, "Case White," the invasion of Poland, was executed. On 3 September, at 11 a.m., with the expiration of England's time limit imposed on Germany for withdrawal from Poland, a state of war existed between England and Germany. The German Navy began preparing for a shooting war on 19 August. Fourteen Type-VII ocean-going Uboats sortied to sea in the evening. One more sailed on 22 August, followed by another on 23 August. On the same date, seven smaller submarines, referred to as "Ducks," sailed for patrol positions in the North Sea. Seven more Ducks and three Type-VIIs took up patrol positions in the Baltic. The submarines in the Baltic were a precaution if German-Soviet negotiations on an nonagression treaty remained unresolved. It was not until this agreement was signed in Moscow that the Baltic submarines were transferred to the North Sea. Consequently, on the eve of the war in Europe, the German Navy was able to position 34 of its 57 U-boats near England.
Adolf Hitler ordered Adm. Raeder, Commander Reichsmarine (German Navy) to instruct U-boat commanders to adhere to the 1930 Submarine Protocol, which Germany signed in 1936.
Specifically, article 22 which stated:
"That with certain exceptions, ships were not to be sunk without warning. They were to be stopped and inspected, or visited and searched. If found to be an enemy ship or a neutral ship with contraband, inbound to a hostile port, they could be sunk, after the safety of the crew had been absolutely assured." Exceptions allowed under the 1930 Submarine Protocol were:
"Troopships, vessels in a convoy, ships escorted by warships or aircraft, and vessels taking part in enemy actions."
The British Admiralty defined a convoy as: "All ships whether combat, auxiliary, merchant, or troop transport, which travel together as a unit." Samuel Eliot Morison defined a convoy as: "The supply train and reinforcement column of the sea. A group of merchant vessels or troop transports, highly vulnerable to surface or submarine attack when alone, steaming in company, escorted by warships." Prior to the United States entering the war in December 1941, North Atlantic convoys averaged 45 to 60 merchant ships, positioned in nine to 12 columns, 1000 yards between columns, and 600 yards between ships.
After England declared war on Germany, the German Naval staff in Berlin, the Oberkommando der Kriegsmarine or OKM, at 12:56 p.m., sent a coded message to German warships at sea: "Hostilities with England effective immediately." At 2 p.m., a second coded message stated: "U-boats to make war on merchant shipping in accordance with operations order." A third coded message was sent at 3:50 p. …