On her third war patrol, 26 May to 1 July, she landed six Philippine guerrillas on a small island near Balabac Strait 8 June. Proceeding to scout the enemy naval base at Tawi Tawi, she sank the 5,142-ton Japanese tanker "Asanagi Maru" on 11 June. She also warned American forces in the Marianas of the departure from Tawi Tawi of the Japanese task force that was later defeated in the Battle of the Philippine Sea on 19 June and 20 June. Operating off Leyte on 24 June, she sank the 3,028-ton Japanese passenger-cargo ship "Aso Maru", before returning to Fremantle.