March 1943: Missed Opportunity

The best month for U-boats fighting North Atlantic convoys wasn't early in the war but rather late--March 1943. "Gray wolves" scored against six eastbound convoys, sinking a total of 40 ships. The greatest success was achieved during the battles with convoys HX 229 and SC 122. Twenty two merchant vessels were sent to the bottom. Alarmed, Churchill was determined to redouble efforts against the reich's submarines, and sink one of every three that left port.

The German success of March 1943 has been exaggerated by some historians, who claimed it came close to severing the Allied supply line in the North Atlantic. Prior to Blair's second volume, which challenged the claim, it was common to assert that the reich came close to winning the Battle of the Atlantic. In fact, as Blair noted, the losses of March 1943 represented only about 8% of allied ships sailing that month in eastbound convoys.

The significance of the German success may have have been overblown. Is it possible, though, the Germans could have won the Battle of the Atlantic, even if they did not?

In The U-Boat Wars, Edwin Hoyt covered March 1943 in the chapter "The Jaws of Victory." Like a number of other authors, Hoyt considered the situation, after "the enormity of the disaster," to be "very black indeed." It wasn't that bad, but Hoyt included something which suggests the Allied situation could've become significantly worse.

During the pivotal battle against HX 229, Hoyt wrote that at one point the convoy was defenseless as its escorts were all busy rescuing survivors or chasing U-boats. Yet, despite a golden opportunity to inflict more losses, "four perfectly sound U-boats failed to attack." He did not say which U-boats they were; perhaps U-228, U-439, U-448 and U-445. None seem to have had aggressive commanders as they never hit anything. But what if they did attack? Given lack of escorts, it wouldn't have been difficult for the four to sink an average of two each, or 8 total. That would've doubled the score that night (March 16-17). Even as escorts returned or reinforcements came, the need for additional rescue operations would've prolonged the defenseless state of the convoy. If this situation persisted another 48 hours--until dawn on the 19th, when U-boats broke off attacks--HX 229 might've been annihilated. Instead of sinking a total of 13 ships the Germans might've sunk over three dozen. They had no shortage of boats; over 40 were available to fight HX 229 and SC 122. Destruction of the former would've boosted the total loss to about 45 ships, or over twice the historical toll. The total haul for March (just HX/SC convoys) would've been around 65.

Destruction of an additional 25 ships wouldn't have won the war. Even worse than the material losses, however, would've been the psychological blow. Annihilation of a whole convoy would've undermined faith in the convoy system. It could've badly hurt morale. After a slaughter like that, at the first sign of U-boats, many ship masters would've ordered their vessels to leave their convoys. Sinkings might've remained high even in the spring when, historically, the U-boat casualties of "Black May" effectively decided the Battle of the Atlantic. That could've been avoided, or mitigated.