Operation Navy Help Darwin was a disaster relief operation initiated by the Royal Australian Navy (RAN) following the destruction of Darwin, Northern Territory by Cyclone Tracy during the night of 24–25 December 1974. 13 ships, 11 aircraft, and 3,000 personnel were sent to Darwin in the largest disaster relief operation undertaken by the RAN in its history. The RAN task force was present from 31 December 1974 to 31 January 1975.