At 13.19 hours on 18 Sep 1939, U-35 came across the British steam trawler St. Alvis west of the Hebrides. Lott noticed that the 13 men of the crew could never reach land in the overloaded lifeboat, so he allowed the trawler to proceed after they thrown the radio equipment overboard. In return, the U-boat was warned about the presence of HMS Ark Royal (91) in the area and Lott was asked by the master of the trawler to tell him the name of the commander to report his behaviour to the government, but he refused.

Later that day, the U-boat stopped a group of three trawlers west-northwest of St.Kilda. First the Arlita was sunk by gunfire at 18.48 hours, followed by the Lord Minto at 19.00 hours. The third trawler, Nancy Hague, was allowed to proceed after taking over the crews of the other vessels.