 Complete the following phrase:  During 1977 and 1978, Hobart underwent a half-life modernisation, during which the propulsion system was converted from furnace oil to diesel fuel, and a Naval Combat Data System was installed. In July 1979, Hobart and the Antarctic Support Vessel Thala Dan were sent to Macquarie Island to retrieve a badly injured researcher and return him to Australia. In order to transfer the researcher to the ship, Hobarts personnel constructed a makeshift helipad, which was used by Thala Dans helicopter to deliver the injured man to the destroyer. Hobart remained in Australian waters during the early 1980s, with the exception of deployments to Hawaii for RIMPAC, to the North West Indian Ocean for 6 months in 1981 and participation in Kangaroo exercises. The destroyer underwent refit in 1984. In 1985, Hobart sailed to Canada to represent Australia at a naval review recognising the 75th anniversary of the Royal Canadian Navys founding. During 1986, the ship was deployed to South-east Asia, which was repeated in 1987. During early 1988, the destroyer participated in activities celebrating 