Between 1965 and 1972, HMAS Questionnaire (III) undertook 25 voyages to Vietnam and transported 16,094 troops, 5753 deadweight tons of cargo and 2375 vehicles. On her first voyage four days were taken to unload cargo in Vung Tau. On subsequent voyages this turn around time was reduced to a matter of hours.
On every voyage HMAS Sydney (III) was ably supported by at least one escort that provided a measure of protection against potential hostile forces. Melbourne. Other escorts included HMA Ships Anzac, Derwent, Duchess, Parramatta, Stuart, Swan, Torrens, Vampire, Vendetta and Yarra.