2nd Escort Group ( Royal Navy ) The 2nd Escort Group ( 2 EG ) was a British anti - submarine formation of the Royal Navy which saw action during the Second World War , principally in the Battle of the Atlantic . 2 EG was formed in April 1943 , one of five such support groups formed at the crisis point of the campaign . It was to act as reinforcement to convoys under attack , with the capacity to actively hunt and destroy U - boat s , rather than be restricted to escort duties . Comprising six sloops of the " Black Swan " - class , the group was led by Captain F . J . " Johnnie " Walker , Britain ' s most successful anti - submarine warfare commander , in . The combination of an active hunting group and a charismatic , determined and innovative anti - submarine specialist such as Walker proved to be a potent force ; 2 SG was the most successful anti - submarine unit of the war , being credited with the destruction of 23 U - boats during two years of active service . Formation . Officially called 2nd Escort Group , ( more commonly referred as the 2 SG ) was formed in April 1943 , one of five such groups . Its purpose was to provide reinforcement to convoys at sea , being equipped to spend extended periods at sea moving from one convoy to another as needed . Its function primarily was to assist a convoys escort in its defence , though it also had the facility to spend time , which escorts did not have , to continue attacks on U - boats to successful conclusion rather than having to break off to maintain the guard on the convoy . Walker however was determined that the group would be active in destroying U - boats and impressed this aim on his commanders from the outset . The group comprised six sloops of the Black Swan class , making it a highly uniform group , and the sloop design was well suited to the task , with good endurance , adequate speed and specialized anti - submarine armament . In addition Walker had developed a range of A / S tactics , which 2 SG became adept at , such as the " creeping attack " and the " barrage attack " . The group originally comprised : During April the group was engaged in working up and training ; " Starling " , " Wild Goose " and " Kite " were new ships , and none had worked together before . Under Walkers training ( previously the Experimental Commander at HMS " Osprey " , the RN Anti - submarine training school ) the group became a highly effective and successful unit . History . First patrols . The group ' s first patrol in May 1943 was uneventful . There were several major convoy battles during the month , but none involving 2 SG . The group operated in support of HX 235 and ONS 8 , sailing ahead in an attempt to encounter and breach any U - boat patrol lines drawn across the convoy routes . The group ' s first success came in June . Its first U - boat was detected on 1 June 1943 : fortuitously on a fine day , and identified by a Lt . Earl Howe Pitt , the event was dubbed another " Glorious First of June " by Walker . Over a 15 - hour period the group found , tracked and destroyed , in the longest hunt of the Atlantic campaign up to that point , and a vindication of the support group ethos , leaving ships free of escort responsibilities to destroy U - boats . Bay offensive . After a refit at Liverpool , after which " Cygnet " departed to another group , 2SG was assigned to " Operation Musketry " , an attempt in concert with Coastal Command to interdict the U - boat transit routes across the Bay of Biscay . On 24 June 1943 the group was successful in destroying and , though " Starling " was damaged in the process of ramming " U - 119 " and was forced to retire . Walker elected to stay with the group , exchanging commands with " Wild Goose " , and , after the group returned to port , with " Kite " . 2 SG was joined at this point by ( Lt . Cdr C . Gwinner ) , as replacement for the damaged " Starling " . On 30 July 1943 Walker ' s group saw further success when they encountered a group of three U - boats on the surface ( two were vital submarine type XIV replenishment boats known as " Milk Cows " ) while in the Bay of Biscay . He signalled the " general chase " to his group and fired at them , causing damage that prevented them from diving . Two of the submarines , , a Type XIV , and , a Type IX / C40 , were then sunk by Walker ' s group , and the second Type XIV , , by Australian Short Sunderland aircraft . But whilst the remainder of the operation saw the destruction of 20 U - boats over a nine - week period , 2 SG ' s time was unproductive , and no further successes were recorded . Atlantic operations . In September 1943 , after a further refit , 2 SG went to the North Atlantic , in company of the escort carrier . The group was joined by ( Lt . Cdr R . S . Abrams ) , while " Woodpecker " was in for repairs . In October , in concert with B - 7 Escort Group , the group worked in support of ON 207 . No successes were recorded , though the convoy battle saw three U - boats destroyed , with no ships lost . However in November 1943 , in operations around HX 264 , 2 SG accounted for two more U - boats , and . Whilst the United States Navy had had much success using carrier groups in a hunter killer role on the mid - Atlantic route , the Royal Navy ' s experience was less positive . Winter gales made flying difficult and hazardous , while the need to provide protection to the carrier hampered A / S operations . 2 SG at least generally had more success operating without carrier assistance . On December 2 SG was acting in support of SL 140 / MKS 31 with 4 SG ( Cdr . E . H . Chavasse ) . 2 SG put in a determined attack on a U - boat , ( thought to be ) , but was unsuccessful , though the battle for SL 140 / MKS 31 saw the destruction of a U - boat , without loss of ships . Six in one trip . In January 1944 2 SG sailed on its most famous exploit , accounting for six U - boats in one patrol , three of them in one 15 - hour period . On 31 January 1944 Walker ' s group gained their first kill of the year when they sank . On 9 February his group sank , , and in one action , then sank on 11 February , and on 19 February . This patrol was ended on 20 February 1944 , when one of Walker ' s group , , was torpedoed ( possibly by or by ) . After an 8 - day struggle to get her home , " Woodpecker " sank in a gale off the Scillies ; all of her crew were saved . " Woodpecker " was the only ship of 2 SG lost in action . The group returned to its base at Liverpool to the thrilled jubilation of the city ' s inhabitants and the Admiralty . The First Lord of the Admiralty was present to greet Walker and his ships . Walker was promoted to Captain and awarded a second Bar to his DSO . Arctic convoy . In March 1944 the group returned to North Atlantic , destroying on weather patrol , before joining Arctic convoy JW 58 . It was joined in this for a short period by . 2 SG met and destroyed in transit across the " Rosegarden " , but had no other success , though three U - boats were destroyed in attacks on JW 58 . The return convoy , RA 58 , was also attacked but neither side saw any success . In May 1944 , 2 SG responded to an attack on by . Though starting from 300 miles away Walker , in an inspired piece of work , divined where to search and after a three - day search gained contact . An 18 - hour hunt brought " U - 473 " to the surface , where she was sunk by gunfire . In June 1944 , 2 SG was joined by , , and , replacements for " Kite " and " Magpie " . That month the group was on search and destroy operations in the South - Western Approaches , as part of " Operation Neptune " - the invasion of Normandy , and was instrumental in preventing any attacks on the invasion fleet . In all fifteen U - boats were destroyed in attempts to attack the invasion fleet . Eight ships were sunk . On July 2 SG received its heaviest blow when Capt . Walker died suddenly of a . Later operations . In July 1944 , 2 SG was back in action , led initially by " Dominica " ( Cdr . N . A . Duck ) and later by " Wild Goose " ( Cdr . D . E . G . Wemyss ) . The group had one successful patrol during August operating in the Bay of Biscay . Four U - boats , , , , and were accounted for while attempting to cross the bay to and from their bases . The months following this were unfruitful , however , as the U - boat Arm changed its tactics to operate in the shallow inland waters around Britain , using the " schnorkel " to remain submerged for entire patrols . This created a different set of tactical problems , requiring different tactics of the escorts . Last successes . In 1945 " Loch Fada " and " Loch Killin " were transferred , to be replaced by , , and . As 2 SG grappled with the changed nature of the campaign the group saw its last successes . In February 1945 the group destroyed two more U - boats , and ( some sources say this was ) . 2 SG was also credited with , bringing its score to 23 . Wemyss reports the attack , in March 1945 , but after a report of another sinking in the same area six months earlier , concluded they were " flogging a dead horse " . However a post - war report of " U - 683 " missing in the area led to 2 SG being credited with her destruction . More recent analysis has questioned this , and the assessment was changed in 1989 . It is now thought that 2 SG ' s attack was on the wreck of , sunk in September 1944 . Despite this , 2nd Support Group was responsible for the confirmed destruction of 22 U - boats during World War II , making it the most successful anti - submarine unit of the entire conflict .