Castlemaine entered service with a compact specialist crew

Castlemaine commissioned on 17 June 1942 under Philip Sullivan, a former coastal passenger-ship master. Her seventy-nine-person complement covered command, seaman, engineering, communications, supply, and medical duties, including anti-submarine and gunnery specialists. Added wartime equipment eventually raised the total to eighty-nine. She embarked twenty depth charges at Swan Island before sailing to Sydney, where completion work included an LL sweep and two bridge Oerlikon guns. Only three days of work-up in Broken Bay preceded convoy duty between Sydney and Melbourne. That short period could begin to build teamwork among an inexperienced crew, but offered little time to turn them into a fully trained fighting unit.