Western Australia did not operate a colonial navy in the years before federation. Since Western Australia did not achieve self-government until 1890, the colony was forbidden from operating its own naval vessels under the Colonial Naval Defence Act of 1865. However, in 1879 a militia unit, known as the Fremantle Naval Artillery was formed to assist in the defence of Fremantle Harbour. The naval artillery unit was made up of ex-Royal Navy men and merchant seamen of good character.
The unit was equipped with two brass 6-pounder field guns; these guns had no limbers, restricting their movement. These guns hindered the primary function of the naval artillery, which was to provide a mobile shore battery for the defence of Fremantle Harbour. In 1889 these guns were replaced by two 9-pounder guns, complete with limbers and wagons. The Fremantle Naval Artillery was eventually disbanded and reformed as the Fremantle Artillery Volunteers.