Turning the Tide: How a Small Band of Allied Sailors Defeated the U-Boats and Won the Battle of the Atlantic
By Ed Offley
(Basic Books, 478 pages, $28.99)

It’s not that the story of the Battle of the Atlantic hasn’t been told often and well. But Ed Offley’s Turning the Tide is a dramatic contribution to understanding of a long-running and geographically huge confrontation that may have mattered more to the outcome of World War II than more commented-on campaigns.

Offley puts his painstaking re-creation of events together from Allied and German archives, memoirs, previous published accounts, as well as from interviews with survivors of the convoys, both merchant and navy sailors. He tells the big picture story with statistics, timelines, and overviews of strategy, tactics, and equipment involved.

As important and engaging as the sweep and generalities of the largest naval campaign in history are, the bulk of this book, and Offley’s signal contribution, is his first-hand, blow-by-blow descriptions of some of the deadliest and most game-changing encounters of the Atlantic war. Offley shows readers the battle as it was seen by those engaged in it, from ordinary seamen to admirals.

Offley, a long-time military reporter and navy veteran, puts readers of Turning the Tide on the bridge, in the engine rooms, in the U-Boats, and all too often in the life boats or into the icy North Atlantic water with nothing more than a life-jacket. (Being in a U-boat was hell for many reasons, not least of which was because of limited space and very limited fresh water, U-boat sailors could only bring one suit of clothing and could not shower during combat patrols that lasted four to six weeks.) Readers see the two sides duel with each other and with the North Atlantic itself for personal survival, for the survival of Britain, and for the survival of the Allied cause in that all so personal, small-picture way that all wars are fought by the individuals who must bear the sometimes crushing burdens. Some of this, I’m obliged to say, is not for feint-hearted readers.

It’s impossible to overestimate the importance of the Battle of the Atlantic. And not just because it lasted from the beginning of WWII in 1939 to the end of the European war in May of 1945, covered a significant fraction of the planet, and led to the loss of many hundreds of ships and tens of thousands of lives. Most participants in this battle, and those who watched it from afar, clearly understood that if German U-Boats could starve England out of the war the Allies would have been denied the near springboard from which to invade Fortress Europe. (Just imagine the logistics involved in invading France from New Jersey.) Losing the Battle of the Atlantic could have meant losing the war. At the least it would have meant the war lasting past 1945.

To survive itself, and to support the large invasion force of Allied troops who would train there, conduct a huge strategic bombing campaign from there, and eventually invade Nazi-held Europe from there, the United Kingdom, an island nation whose economy and populace had historically depended on imports, had to continually receive huge amounts of food, petroleum, war material and other vital supplies by sea. Even with convoys continually arriving, strict food rationing lasted through the war and even after in the UK. By 1942 U-boats had reduced food supplies to the point that the average Brit civilian could look forward to only 12 ounces of bread and two ounces of tea per day. Meat allotments got down to four ounces of ham or bacon per week and one egg every two weeks.

The early rounds of the battle went to the Germans. With few escort ships or protecting aircraft available and anti-U-boat tactics not developed yet, the Nazi boats had a field day off the U.S. East Coast at the beginning of the war. U-boats sank 229 merchant ships there during the first half of 1942, and almost 400 ships in the Gulf of Mexico, Caribbean Sea, and North and Central Atlantic during the same period.

Fortunes of the battle changed multiple times over the next three years as the convoy system was developed and more ships and planes became available to protect the merchantmen. But the contest wasn’t just decided by the bravery and seamanship of allied sailors and the effectiveness of new tactics, as important as these things were. And it wasn’t decided totally by the amount of floating and flying stock available. There was also the critical electronic battle, fought by scientists, technicians, and code-breakers ashore. A major break for the Allies came with the fortuitous capture of a German naval Enigma code machine from an abandoned U-boat and the breaking of the enormously complex code that went with that system.

Changes in weaponry — new types of torpedoes and the development of the hedge-hog, forward-firing mortar system — as well as developments in radar and other detection and tracking technology, gave first one side then the other an edge for a bit until the next development or refinement came along. The Allies finally captured the technology edge and held it to the end of the war. 

Much of Turning the Tide is devoted to a detailed narrative of the almost continuous combat endured during the ill-fated trips of eastbound convoys SC122 and HX229 as well as the westbound convoy ONS5. These convoys took place during March and April of 1943, the peak of the effectiveness of the U-boats, and the most worrisome time for the Allies.

The huge losses of these convoys led both British and American leadership to put more ships and planes into the Atlantic fight. These much-needed reinforcements along with technical breakthroughs soon gave the Allies the upper hand, which they never relinquished. England was saved, Fortress Europe was invaded from the Sceptered Isle, and fascism was denied. It was a close business.

With the somber totaling up after the war, we learned that almost 10,000 U.S. Merchant Marine crewmen had died during the battles in the Atlantic. British and Commonwealth merchant sailors fared even worse, with more than 37,000 crewmen lost. The British and Commonwealth fatality rate for merchant seaman was 17 percent, almost three times the fatality rate of the British Army.

As bad as these numbers are, it was much more dangerous to serve on a U-boat. Of the 830 U-boats that put to sea in WWII, 717 were lost in combat or to accidents. Of 39,000 German sailors who went down to the sea in U-boats, 27,490 perished, yielding an almost unbelievable 70 percent fatality rate, making German U-boats the most dangerous branch of any service of any nation during WWII.

Offley skillfully blends history and statistics and analysis as well as heart-pounding narratives of sea-battles that have the immediacy of a good novel, only they tell of real people and real events. Turning the Tide is a long and detailed book that belongs on the bookshelves of professional historians or of general readers attempting to understand a central campaign in the most horrific war in human history.