Escort Group B6 Escort Group B6 was a British convoy escort group of the Royal Navy which saw action during the Second World War , principally in the Battle of the Atlantic . Formation . Escort Group B6 was one of seven British escort groups which served with the Mid - Ocean Escort Force ( MOEF ) , which provided convoy protection in the most dangerous midsection of the North Atlantic route . The MOEF was originally to be 5 American , 5 British and 4 Canadian groups . B6 was formed in the spring of 1942 , following the inability of the US Navy to form groups A4 and A5 due to other commitments . To replace them two new escort groups , B6 and B7 were formed . Service history . Led by V class destroyer " Viscount " , and under the leadership of Commander John Waterhouse , B6 included four Norwegian - manned Flower - class corvette s from A4 ; " Acanthus " , " Eglantine " , " Potentilla " , and " Rose " . These were joined later by a fifth , " Monbretia " . In the summer of 1942 B6 escorted several uneventful convoys which arrived without loss . However in August 1942 ON 122 was attacked by 9 U - boat s of wolfpack " Lohs " . four ships were sunk , while six U - boats were damaged , four seriously enough to return to base . Two of these returning submarines were attacked by aircraft in the Bay of Biscay ; one was sunk , another so badly damaged it had to be withdrawn from service . In September B6 was joined by the F - class destroyer " Fame " as senior ship , whose commander Ralph Heathcote became Senior Officer of the Escort group ( SOE ) . In October SC 104 was attacked by Group " Wotan " In a 5 day battle ( 12 - 17 Oct ) SC 104 lost eight ships while two U boats ( " U - 661 " and " U - 353 " ) were destroyed and two others damaged . During this action both " Fame " and " Viscount " were damaged and forced to withdraw , command falling on Lt - Commander Christian Monsen of " Potentilla " . In November a depleted B6 group , still under Monsen , was escorting ON 144 which was attacked by 16 U boats of Group " Kreuzotter " . In a fierce battle , 5 ships of the convoy , and the corvette " Monbretia " , were sunk . One U - boat was destroyed ( " U - 184 " , sunk by " Potentilla " ) . Monsen and the group were later commended for their aggressive defence , which was widely held to have averted a major disaster . In December HX 217 was attacked by seven U - boats of group " Panzer " . B6 , again led by " Fame " , and with the three Norwegian ships was now joined by the Polish destroyer ORP " Burza " , and a British corvette . Another aggressive defence kept losses to a minimum , even when " Panzer " was joined by a second wolf pack , " Draufgang " . Two ships were sunk in the three - day battle , while one U - boat was sunk by aircraft , and several others damaged . Another U - boat was lost , and one damaged , in a mid - ocean collision In January 43 B6 was joined by the corvettes HMS " Kingcup " and " Vervain " , bringing its strength up to 7 warships . In February 1943 while escorting ON 165 , the convoy was attacked by U - boats of Group " Hardegen " . Two U - boats were destroyed - " U - 69 " sunk by " Fame " and " U - 201 " by " Viscount " - for the loss of two ships . In late February and early March HX 227 was intercepted by group " Neptun " , but an aggressive defence and foul weather frustrated any co - ordinated attacks . Two stragglers were lost , while two U - boats were forced to return with damage . Following the major convoy battles of May 1943 , which left B6 and their charges unscathed , the Battle of the Atlantic fell into a lull as the U - boat Arm withdrew from the battle . Several uneventful convoys followed , until the renewal of the offensive in the autumn of 1943 . In this period B6 was involved in one convoy battle , while escorting ON 206 . This convoy , and ONS 20 , both became embroiled in the last major convoy action of the campaign , which saw six U - boats destroyed , for one ships lost . None of these were accounted to ships of B6 however . Following this action the North Atlantic route was again quiet , with B6 continuing escort duties , until in the spring of 1944 it was disbanded in a general re - organization prior to the invasion of Normandy . In its 23 month career B6 escorted 31 convoys , losing 19 ships , but seeing over 900 safely to harbour . The group lost one of its number , the corvette " Monbretia " , but was credited with the destruction of five U - boats .