Berlin, Germany · November 29, 1939

On this date in 1939, nearly three months after the Wehr­macht (German armed forces) over­ran neigh­boring Poland, launching World War II in Europe, Ger­man dicta­tor Adolf Hitler issued Fuehrer Direc­tive Num­ber 9, the first of two direc­tives on mea­sures his coun­try would have to take to ren­der the Brit­ish econ­omy and in­fra­struc­ture in­cap­able of sus­taining the war against Nazi Ger­many. Titled “Instruc­tions for War­fare against the Eco­nomy of the Enemy,” the focus of Direc­tive Num­ber 9 was on attacking Brit­ish mer­chant and escort ves­sels, de­stroying port instal­la­tions, and block­ading the sea lanes leading to them by using U‑boats, mines, and S‑boats, or E‑boats as these fast torpedo boats were known to the Allies.

The Brit­ish and later their North Ameri­can allies responded with naval and aerial con­voy sys­tems to pro­tect the water life­line to the Brit­ish Isles in this Battle of the Atlantic. The second of Hitler’s directives, Num­ber 23, “Directions for Opera­tions against the Eng­lish War Eco­nomy,” issued on Febru­ary 6, 1941, acknow­ledged that the mea­sures taken during the pre­ceding four­teen months had not so far had any “dis­cern­ible” effect on Brit­ish morale or their capacity to “resist.”

With the pros­pect of moving sub­stan­tial Luft­waffe units from the French Chan­nel coast to the East­ern Front for Opera­tion Bar­ba­rossa (June 1941), Germany’s planned liqui­da­tion of the Soviet Union in eight to ten weeks, Hitler thought it was pos­sible to keep the Brit­ish off balance by pro­gres­sively stepping up sub­ma­rine opera­tions against mer­chant shipping in co­or­di­nation with bombing the key centers of mili­tary air­craft pro­duction to both in­flict the greatest pos­sible damage and simu­late the appear­ance of a Ger­man in­va­sion of their isles, code­named Opera­tion Sea Lion. (The one small-scale Sea Lion test exer­cise off Bou­logne, south­west of Calais in Ger­man-occu­pied North­ern France, con­ducted in good wea­ther and good visi­bility, with no navi­ga­tion hazards or enemy defenses to con­tend with, por­tended a dicey, even un­suc­cess­ful am­phib­ious assault on South­ern Eng­land.) Thus, the period from 1940 to 1942 repre­sented the best chance Ger­many had to win the Battle of the Atlantic: indeed, during this time frame a total of 973 Allied ships were lost. And up through 1943 the Kriegs­marine, with as many as 100 U‑boats at sea at any time (Janu­ary 1943), came terrifyingly close to winning the Battle of the Atlantic.

German U-Boats and the Earliest Days of the Battle of the Atlantic

Hvalfjord Allied naval base, Iceland, late June 1942British escort destroyer on antisubmarine duty, October 1941

Left: Escorts and merchant ships at the Hvalfjord (Hval­fjörður) naval base, Ice­land, late June 1942. During World War II nearly one-third of the world’s mer­chant shipping was British. Out of 36,000 mer­chant sea­men who lost their lives between 1939 and 1945, over 30,000 were from the Brit­ish Mer­chant Navy. More than 2,400 British ships were sunk out of the total of 2,900 Allied ships lost, or a loss of 14.6 mil­lion gross tons. A little over 9,500 U.S. mer­chant marines died at sea, in POW camps, or of their wounds out of the roughly 243,000 who served. (The U.S. govern­ment never kept accu­rate records for its mer­chant marine.) Most of the ships sunk during the Battle of the Atlantic were not in convoys, but sailing alone, or had become separated from convoys.

Right: Officers on the bridge of an escorting British destroyer keep a sharp look­out for enemy submarines, October 1941.

U-boat shells merchant shipTorpedoed U.S. tanker "Dixie Arrow," March 26, 1942

Left: An unnamed U-boat shells a merchant ship that had remained afloat after being torpe­doed (no date). The focus on U‑boat suc­cesses—the “aces” and their scores, the num­ber of con­voys attacked, and the ships sunk—ob­scures the fact that during the Battle of the Atlantic only 10 per­cent of trans­atlantic con­voys were ever attacked, and of those attacked only 10 per­cent on aver­age of the ships were lost. Over­all, more than 99 per­cent of all ships sailing to and from Great Britain during World War II did so safely.

Right: The 8,046-ton U.S. tanker Dixie Arrow was torpe­doed by U‑71 on March 26, 1942. The ship is shown crumbling amid­ships under the heat of fire. Between June 1, 1941, and May 31, 1943, the U‑71 carried out ten war patrols. Operating out of the huge U‑boat pens at St. Nazaire in occupied France, U‑71 on her fifth foray sank 38,894 tons of shipping between March and April 1942. She was scuttled on May 2, 1945, in Wilhelms­haven, Germany, several days before the country’s surrender.

"U-288" under attack, April 3, 1944Operation Torch convoy, November 1942

Left: A Grumman TBF Avenger of the Royal Navy’s Fleet Air Arm fires its machine gun at the conning tower of U‑288 during a con­voy run to the Soviet Union, April 3, 1944. The U‑boat was eventually sunk by rockets and depth charges. Forty-nine men died; there were no sur­vivors. The Kriegs­marine lost a total of 783 sub­ma­rines and 30,000 sail­ors during the war. Despite their best efforts, Ger­man sub­ma­rines failed to stop the flow of stra­te­gic supplies to Britain. Between existing Allied mer­chant ships, U.S.-built Liberty ships (totaling 38.5 million tons), and hundreds of British-built Empire ships, the Allies launched millions more ship tonnage than the 14 million tons of shipping lost to the U‑boat menace.

Right: At the height of the Atlantic campaign U-boats failed to hin­der or even detect the U.S. invasion fleet headed to North Africa in November 1942 (Opera­tion Torch), and they failed to pre­vent the buildup of troops and supplies needed for the D-Day landings in June 1944. As early as May 1943, when a fifth of his U‑boats was sunk in “Black May,” Grand Admiral Karl Doenitz conceded that Germany had lost the Battle of the Atlantic.

U-Boats of the Kriegsmarine and the Earliest Days of the Battle of the Atlantic