They remained in Darwin for 18 months before being relieved and sent back to Melbourne in April 1943. After taking leave, the 7th Battalion was sent to the Atherton Tablelands in Queensland for a period of intensive pre-deployment training in November. In 1944 the 23rd Brigade had been attached to the II Corps, which was tasked with taking over from the Americans and launching a renewed offensive on Bougainville. The 23rd Brigade was given the task of relieving the garrisons in the outer islands and the 7th Battalion was primarily responsible for Mono island, although one company was detached to Munda, arriving there in October 1944. Tasked with defending the airfield from a Japanese attack that was at best remote, some members of the battalion sought to enliven their existence by acting as crews on US Navy PT boats carrying out raids on New Britain and New Ireland.