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, (a cart used for supporting an artillery piece in transit) 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.