The final period opened with preparations being made for 

 the invasion of the Continent, 5 June 1944. Every ore caution 

 was taken by the Allies against U-boat attacks on the invasion 

 fleet. Ten escort groups effectively walled off the western 

 approaches to bhe English Channel, and sea and sir patrols 

 covered the routes which U-boats might use to approach from 

 K or we 3 i an wa t er s . 



During June, 2o U-boats were nk tnd U-505 ! :--' capture 1 

 by the escort carrier jjroup hich Included USS "iuADALCATCAL, 

 USS CHATELAI] 1 id USS PILLSBURY. 



The Schnorcheling tactics of the U-boat were providing 

 effective protection linst attacks by Allied aircraft and 

 dependence in liscavering U-boats had to be almost exclusively 

 on sonar gear. 



The Allied break-through out of the Cherbourg peninsula 

 during bhe first week in August 1944 forced U-boats to move 

 out of the Bay of Biscay ports and take refuge in Korwegiar 

 harbors where the facilities for maintenance and repair were 

 limited and t] e irotection against Allied bombing was far ■ 

 lo?^ effective* Late in 1944, the Germans attempted to make 

 use of their fleet oi 1 ' Ige t ib larines, but the effort was 

 far f -"" ' s ' ccessful „ 



January 1945 saw six U-boats sunk, all by surface ships. 

 Allied nilitary operations on land were bringing about further 

 deterioration of the German U-boat position, with bhe Ri;.ssian 

 advance in bhe Baltic area overrunning the facilities for 

 the fabrication and assembly of new J-bosts. 



German U-boat cc inlanders attempted to defeat Allied sonar 

 gear by spend! ; lor periods on the bottom. But sonar opera- 

 tors soon gained experience in countering bhese new tactics 



nd in Pe >ruary 1945 bhe sir. ; of snemy submarines mounted 

 "':■: 19. Of this total, 5 were Japanese submarines in the 

 Pacific, where the American submarine, USS BATFISE, succeeds 3 

 in sinking three I-class Japanese submarines within four days. 



During the early days of hay, bhe U-bcat fleet carried 

 on a- thou h oblivious to tl e approaching lisaster bo the 

 German land forces. On 5 Lay 1945 an American c vessel 

 was sunk off R3 "■. Island, but the attacking U-boat was 

 destroyed later the sane lay. On 7 Lay two ships were sunk 

 by a U-boat off the Firth of Forth, T^ese were the last 

 Allied merchant vessels to he sunk by 'U-boats durinq World 



vy 



