(Lightbody, 2004, p. 178) The Germans attempted to counter these stratgies with the deployment of the XXIII and XXI improved U-boats. These new U-boats were able to achieve higher speeds underwater, which were increased to approximately 20 knots, compared to the average 4 knots of the previous U-boats. (Lightbody, 2004, p. 178) They were also capable of operating at twice the depth of the ordinary U-boats and had had six torpedo tubes in place of the four on conventional craft. The new U-boats also had a hydraulic loading system, which was a radical improvement of the manual loading systems in older models. (Lightbody, 2004, p. 180)

These various countermeasures and improvements instituted by the German's were not enough to stop the decline of the influence of the U-boat in the Atlantic. One of the central issues that brought about this situation was the Germans did not address the infiltration of their encryption intelligence. The British and the American had been working on breaking the Enigma code which the U-boats used for communication.

Many studies claim that "The breaking of the Enigma Code virtually was as important to winning World War II as the Manhattan Project." (Kreyche, 2005, p. 80) the Enigma code was a complicated encryption that Germany has been using since the 1920's. Before the code was deciphered by the Allies it had "... plagued the Allies by directing Nazi U-boats to Allied convoys of troop and merchandise shipping.... Wolf packs sunk the ships with abandon, almost to the point of completely cutting off supplies. " (Kreyche, 2005, p. 80) Without the code and due to the various strategies that have already been mentioned which were implemented by the Allies, the U-boats became considerably less effective than in the past. In fact military historians point out that, " the history of the U-boat war from May 1943 to the fall of 1944 is a repetition of German defeat. The U-boat continued to suffer heavy losses without being able to come to attack." (U-boat Restoratives)

4. Conclusion

The German U-boats were certainly one of the most effective weapons in the German arsenal and had the potential of winning the war for Germany. The fact that they were invisible to the destroyers and convoys meant that they were a serious threat to the Allied supply lifeline. While the first few years of the war saw the success of the U-boat, yet various stratgies and technologies were implemented which eventually resulted in the decline of the U-boats and the war of attrition in the ocean was won by the Allies.

However, it should also be remembered that during the war the U-boats were responsible for sinking 2,882 merchant ships and 175 warships, and at the height of their success "...came close to isolating and defeating Great Britain by cutting off essential supplies." (Lightbody, 2004, p. 180) in terms of German losses the most reliable...

(Lightbody, 2004, p. 180) These figures tend to belie the common myth of the heroic U-boat and its invincible crews. In reality, for the men who manned them, they were little more than 'iron coffins'. (Lightbody, 2004, p. 180)