2011 $1 Royal Australian Navy 1911-2011 PNC. The battle cruiser HMAS Australia was the Royal Australian Navy's first flagship. Within the first year it was pressed into action with the outbreak of World War 1. It's two major battle honours were at Rabaul in 1914 and on the North Sea during 1915-18. It was decommissioned on 12 December 1921 after eight years of service. Please contact Adelaide Exchange Jewellers to find out more on this item.