Not sure if it is any help. My father's logs - he was at Limavady from Oct 1940 with 502 Squadron on Whitleys. Some of the escort duties and submarine hunts listed are: 5/4/41 Special Escort SS Avila Star; 7/4/41 Special Escort H.M.S. Hood; 16/5/41 Submarine hunt engaged FW Condor; 28/5/41 Special escort H.M.S "King George V & Rodney" engaged E.A HE.111 & JU88. Then a lot of Submarine sweeps and convoy escorts (about 6 or 7 a month) until 29/3/42 "special escort & search for St Nazaire Commandos. Shortly after he went to Cranwell.