HMAS Australia (1911) fighter—and operated them until the end of the war. The 2nd BCS again supported minelayers in the North Sea between 25–26 June and 29–30 July. During September and October, "Australia" and the 2nd BCS supervised and protected minelaying operations north of Orkney. When the armistice with Germany was signed on 11 November 1918 to end World War I, one of the conditions was that the German High Seas Fleet was to be interred at Scapa Flow. The German fleet crossed the North Sea, and on 21 November, the British Grand Fleet sailed out to meet it; "Australia" led the port
Naval warfare of World War I Fleet defended the port of Sulina throughout the second half of 1916, causing the sinking of one German submarine. Its minelayer also defended the Danube Delta from inland, leading to the sinking of one Austro-Hungarian Danube monitor. (See also Romanian Black Sea Fleet during World War I) When Bulgaria entered World War I in 1915, its navy consisted mainly of a French-built torpedo gunboat called "Nadezhda" and six torpedo boats. It mainly engaged in mine warfare actions in the Black Sea against the Russian Black Sea Fleet and allowed the Germans to station two U-boats at Varna, one of which