administrative control of Commander Australian Forces Vietnam in addition to that of the Flag Officer Commanding Australian Fleet. Operationally, the RAN vessels were under the command of the United States Seventh Fleet. Arrangements were made to provide logistic support through the United States Pacific Fleet. A USN lieutenant was assigned to each ship during deployments to act as a liaison with the Seventh Fleet. The deployment of in March 1967 began a pattern of six-month deployments for RAN destroyers, with a constant RAN presence with the Seventh Fleet. Australia was the only allied nation to provide naval support to the United States Navy during the Vietnam War. First deployment After time in Australian waters to prepare for wartime service, Brisbane arrived in Subic on 28 March 1969 to be deployed to the Vietnam War. Responsibility was handed over from Perth on 31 March, and the ship spent the first two weeks of April undergoing familiarisation exercises and having both gun turrets repaired following equipment failures early on. The destroyer was first deployed to naval gunfire support duties, and arrived off the IV Corps operating area on 15 April. During this period, there was a surge in Market Time activity, and although Brisbane was not assigned to that operation, she was asked to provide gunfire assistance on several occasions. On 5 May, Brisbane was ordered to the Gulf of Thailand to provide support for South Vietnamese forces operating near the Cambodian border. The destroyer was relieved on 18 May by , and sailed to Subic for maintenance. On 10 June, the Australian ship relieved and commenced gunline duties in the II Corps Area. After four days, during which Brisbane and completed a combined 189 fire missions, the Australian ship was ordered north to I Corps to relieve the American cruiser . Here, the Australian ship provided support for 3rd Battalion 3rd Marines during Operation Virginia Ridge. Brisbane returned to the II Corps area on 24 June, but only remained in the area for four days; on 29 June, the ship was relieved by , and sailed to Singapore for maintenance and refit. En route to Singapore, the destroyer encountered the merchant vessel , which was on fire. After unsuccessfully attempting to extinguish the fire, Brisbane evacuated Sinceres crew, and remained in the area until the salvage vessel Salvana arrived to take the stricken vessel in tow. Brisbane returned to operations in