War II, as the Japanese between May 8 and August 14 sank no 

 Allied ships while losing six of their own submarine s 



The early days of May saw one German submarine sunk in 

 the Bay of Biscay channel area and approximately ten in Danish 

 waters', while an estimated twenty-five U-boats were put out of 

 commission by Allied bombing while in port* On 4 May, Admiral 

 Doenitz told his U-boat crews that the battle was hopeless and 

 instructed them to break off further action,, During the re- 

 mainder of May, forty-nine U-boats surrendered in accordance 

 with Allied instructions and a great many additional U-boats 

 were captured in port or were scuttled. The last U-bcat to 

 be accounted for was U-977, which surrendered at Buenos Aires 

 on 17 August 1945 following the Japanese capitulation „ 



In summing up the U-boat war, it should be remembered 

 that at the close of the war, while the U-boat fleet had been 

 held in check and was definitely on the defensive it was far 

 from being driven from the sea. There is no way of estimating 

 the results which the Germans might have achieved with the new 

 types of U-boats which were just about to begin operation as 

 the war ended <> 



The closing period of the war was marked on the part of 

 the Allies by the successful development of new tactics and 

 new equipment. More effective search plans were developed, 

 based on analyses by KDRC scientists, which showed that where 

 the correct plan was used contact with a submarine was re- 

 gained in 44 per cent of the cases, whereas use of an incorrect 

 plan brought a renewal of contact in only 20 per cent of the 

 cases, 



The United States Navy, with the assistance of Division B 

 of NDRC, continued the improvement of its sonar equipment, 

 looking particularly to developments which would permit con- 

 tact to be maintained with deeply submerged submarines at short 

 ranges. 



The confidence which the Germans placed in the effective- 

 ness of the U-boat despite the heavy losses which they suf- 

 fered is evidenced by the fact that, though faced with imminent 

 invasion and suffering from a tremendous shortage of manpower, 

 they employed a great proportion of their skilled workers in 

 the improvement of their U-boats and the construction of new 

 designs. 



Had the Germans been able to put these new types of U-boats 

 into service use there is a chance that they might have made 

 obsolete all the equipment and devices which Allied scientists 

 had developed. 



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