After carrying out a patrol between Lourenco Marques and Durban, during which "U-181" sank three more ships. "U-181" rendezvoused with the supply ship "Charlotte Schliemann" east of Mauritius to refuel on 21 June. Also present were , under the command of Robert Gysae, (Wilhelm Dommes), (Eitel-Friedrich Kentrat), (Robert Bartels) and (Werner Hartmann). The commanders exchanged experiences and discussed the problem of torpedo failures. In July, Lüth led his boat west towards Madagascar, before being ordered back to Mauritius. On 15 July 1943, Lüth sunk the British collier "Empire Lake" and noted in his logbook: "Five men have been left floating on a piece of wreckage. Due to the high sea and 180-mile distance from land they will probably not be saved."