On 20 July 1940 HMS OSWALD (LtCdr D A Fraser) sailed from her base at Alexandria in Egypt with orders for a war patrol to be conducted off the East of Sicily. On 30 July 1940 HMS OSWALD made a torpedo attack on a convoy of seven merchant vessels escorted by four Torpedo Boats to the South of Capo del Armi. The convoy was later joined by four escorting destroyers, one of which, the GRECALE reported a near miss. The attack was unsuccessful. Details of the convoy were reported by OSWALD which then moved to the Ionian Sea.

On 1 August 1940 HMS OSWALD sent a signal reporting enemy cruisers heading Northwards through the Straits of Messina. It is probable that the sending of the signals had alerted the Italians to the presence of OSWALD and, by now, all Italian ASW forces in the area were alerted to her presence and were on the lookout.

On the night of 1 August 1940, she was spotted while running surfaced, charging her batteries, 12 nautical miles South East of Capo Spartivento, Calabria, a scant 2500 meters away by an Italian destroyer division consisting of Ugolino Vivaldi, Nicoloso da Recco, Antonio da Noli and Antoniotto Usodimare. VIVALDI was closest and came about immediately, impacting the boat at 2305 hours and sinking her. The crew of OSWALD abandoned ship but three of them were lost.  Fifty-two survivors were rescued by the destroyers.