At 17.50 hours on 18 June 1940, U-32 tried to stop the unescorted and unarmed Altair (Master Johannes Pedersen) with a shot across her bow south of Ireland, after one torpedo had missed at 17.22 hours. She did not stop and was then shelled by the U-boat until the crew began to abandon ship in two lifeboats. At 19.02 hours, the ship was hit amidships by a coup de grâce and settled with a heavy list, but remained afloat on her cargo of lumber. The wreck was scuttled by HMS Cape Howe (X 02) (A/Cdr E.L. Woodhall, DSO, MVO, RN) in 49°36N/11°22W on 20 June.

At 19.12 hours, U-32 had sighted the two Spanish trawlers Sálvora and Nuevo Ons and sank them because they were outside of the allowed area of fishing. The survivors were rescued by the lifeboats of the Altair. They were picked up later that same night by the Spanish trawler Iparreko-Izarra, which also located an empty lifeboat of Balmoralwood. The men were later transferred to the Spanish trawler Piedi and landed at Pasajes, Spain on 21 June.