This period lasted until 1913, when naval ships purchased from Britain arrived, although the British Admiralty continued to provide blue-water defence capability in the Pacific and Indian Oceans up to the early years of the Second World War.

The navy is one of the largest and most sophisticated naval forces in the South Pacific region, with a significant presence in the Indian Ocean and worldwide operations in support of military campaigns and peacekeeping missions.

[8] In 1908–09, a compromise solution was pursued, with the Australian government agreeing to establish a force for local defence but that would be capable of forming a fleet unit within the Royal Navy, albeit without central control.

The first of the RAN's new vessels, the destroyer HMAS Yarra, was completed in September 1910, and by the outbreak of the First World War the majority of the planned fleet had been realised.

This was to deprive the Imperial German Navy's East Asia Squadron of regional intelligence by removing their access to wireless stations.

On 11 August, three destroyers and HMAS Sydney prepared to engage the squadron at German Anchorages in New Guinea, which did not eventuate as the vessels were not present.

Landing parties were placed on Rabaul and Herbertshohe to destroy its German wireless station; however, the objective was found to be further inland and an expeditionary force was required.

The Australian Naval and Military Expeditionary Force (ANMEF) began recruiting on the same day that the taskforce arrived in New Britain, and consisted of two battalions: one of 1,000 men, and the other with 500 serving and former seamen.

A few days later, on 9 September, HMAS Melbourne landed a party to destroy the island's wireless station, though the German administration promptly surrendered.

Between 11 and 12 September, landings were put ashore at Kabakaul, Rabaul and Herbertshohe; it was during this period that the first Australian casualties and deaths of the war occurred.

On 17 September, German New Guinea surrendered to the encroaching ANMEF, with the overall campaign a success and exceeded the objectives set by the War Office.

Following the almost complete destruction of the East Asia Squadron in the Battle of the Falklands by the Royal Navy, the RAN became able to be reassigned to other naval theatres of the war.

[13] Following the entrance of the Ottoman Empire in alliance with the Central Powers, HMAS AE2 was committed to the initial naval operation of the Gallipoli campaign.

[16] In this time the focus of Australia's naval policy shifted from defence against invasion to trade protection,[17] and several fleet units were sunk as targets or scrapped.

[17] In the late 1930s, as international tensions increased, the RAN was modernised and expanded, with the service receiving primacy of funding over the Army and Air Force during this time as Australia began to prepare for war.

[17] Early in the Second World War, RAN ships again operated as part of Royal Navy formations, many serving with distinction in the Mediterranean, the Red Sea, the Persian Gulf, the Indian Ocean, and off the West African coast.

[25] NHQ is responsible for implementing policy decisions handed down from the Department of Defence and for overseeing tactical and operational issues that are the purview of the subordinate commands.

[40] The highest rank achievable in the current Royal Australian Navy structure is O-10, an admiral who serves as the Chief of the Defence Force (CDF) when the position is held by a Naval Officer.

[citation needed] From January 2021, MSWOs and all chaplains wear the branch's new non-faith-specific rank insignia of a fouled anchor overlaying a compass rose, which represents a united team front, encompassing all faiths and purpose.