Balabac Strait
"Flier" put into Fremantle submarine base, Western Australia, to refit between 5 July and 2 August 1944, then sailed on her second war patrol, bound for the coast of Indochina via the Lombok Strait, Macassar Strait and Balabac Strait. At about 2200 on 12 August, while transiting Balabac Strait on the surface, she struck a naval mine. She sank in about a minute, but 15 officers and men were able to clamber out. Eight of them reached the beach of Byan Island after 17 hours in the water. Philippine guerrillas guided them to a coastwatcher, who arranged for them to be picked up by submarine, and on the night of 30–31 August, they were taken on board by .