"Wainwright" reported her first scrape with a German submarine on 11 May. She sighted an abandoned lifeboat at about 08:00. After investigating the drifting boat for occupants and finding none, she sank the boat with gunfire. At about 08:15, a lookout reported that a torpedo had missed the destroyer some astern. "Wainwright" then fired several rounds from her guns at what was thought to be a periscope. The supposed submarine disappeared soon thereafter; and, despite a thorough investigation of the area, the destroyer could turn up no more evidence of the presence of a U-boat.