Operation Copper was one of the last Z Special operations in New Guinea. On the night of 11 April 1945, eight operatives were landed near Muschu Island by HDML patrol boat. Their mission was to paddle ashore and reconnoitre the island to determine the status of Japanese defences and validate reports that two 140 mm long-range naval guns were still in position. Intelligence suggested that these weapons were back in service and could prove dangerous during the forthcoming invasion of Wewak, as they had sufficient range to fire into the proposed landing areas and, while they would not stop the Australian invasion, they could cause significant casualties.