The fall, on the other hand, brought "Wainwright" increased activity. After spending the first two weeks of September in repairs at Birkenhead, near Liverpool, she departed the yard at Laird Basin at about 07:00 on the 14th to return to Queenstown. Three quarters of an hour into the afternoon watch, she received orders sending her to the scene of a submarine attack against an Allied merchantman some south-southeast of Helvick Head, Ireland. "Wainwright" rang up full speed, made off for the reported location, and began a search for the U-boat in conjunction with a British dirigible and other surface units. Near the end of the second dog watch, she sighted the submarine's conning tower and bow about off.