Australia's largest naval commitment to the Vietnam War was the provision of destroyers, on rotation, to serve on the 'gunline' – delivering naval gunfire support for ground forces – with the US 7th Fleet. HMA Ships Hobart, Perth and Brisbane all served on multiple six-monthly rotations between 1967 and 1971. The Daring Class destroyer, HMAS Vendetta served one tour of duty on the gunline.
The Australian vessels emerged from the gunline largely unscathed but the requirements of operational service placed heavy demands on ships' companies. Gunline destroyers needed to be constantly available to provide support to shore-based forces and to conduct off-shore patrols.
Hobart and Perth were also involved in Operation Sea Dragon along the North Vietnamese coast between 1966 and 1968. Ships serving on Sea Dragon interdicted enemy attempts at seaborne infiltration and resupply along the North Vietnamese coast from the Demilitarised Zone to the Red River delta near Hanoi and often came under heavy and accurate fire from shore-based batteries. For the ships of the RAN serving in the waters off Vietnam, these operations were amongst the most dangerous of the war. In one tragic incident two members of Hobart's crew were killed when the ship was mistakenly attacked by a US aircraft.
For the sailors who came under fire and saw friends killed and wounded, the war was every bit as real as it was for the ground forces in South Vietnam. No one going into an operational area can be sure of what will happen, only with hindsight is it possible to rank the relative danger of one type of service over another.