During World War II, one of the most publicized branches of the German armed forces was the U-Boat Command. At the beginning of the war, the submarine service was unprepared for the conflict to come, and as the war began, a rapid expansion took place, with U-boat construction and crew training assuming a rapid pace. The Germans never had enough U-boats, and as the war progressed, the Allies were able to develop countermeasures, such as long range aircraft, convoy escorts, and the decoding of German Enigma traffic, which slowed down and eventually overcame the effectiveness of the U-boats against Allied shipping. Although over 1,100 U-boats were built, over 800 were unsuccessful or never saw action, but nevertheless, only 30 U-boat commanders accounted for about 800 of the total of about 3,000 merchant and naval vessels sunk by U-boats during the course of the war. And tragically, of the 38,000 men that went to sea in U-boats, only 8000 survived the war.