HMCS (later HMAS)[1] Protector was a large flat-iron gunboat commissioned and purchased by the South Australian government in 1884, for the purpose of defending the local coastline against possible attacks in the aftermath of the 'Russian scare', of the 1870s.

Her small arms consisted of 200 0.45 Martini-Henry rifles Mk IV, 100 breech-loading revolvers, 100 cutlasses and 30 boarding pikes.

In July 1882, motions were brought forward in both houses of the Parliament of South Australia to establish a naval force with the creation of a cruiser-type warship, capable of defending the local coastline and harbours.

At the suggestion of Sir William Jervois, Armstrong, Mitchell & Co. of Newcastle upon Tyne were chosen to build the vessel, named Protector, for about 40,000 to 50,000 pounds sterling.

Around the turn of the 20th century, all Australian colonies were involved in the Boer War in South Africa, when a call from Britain came to help defeat the Chinese secret society known as the Boxers.

[7] Protector was to join an international force composed of sailors, marines, and soldiers from Britain, France, Italy, the United States, Japan, Russia, Germany, and Austria-Hungary—the so-called Eight-Nation Alliance—to protect the lives of foreign nationals and to defend their economic interests.

In the years leading up to the establishment of an Australian Naval Fleet, Protector was active around the southern and eastern seaboards.

After the surrender of these colonies on 17 September, Protector remained based at Rabaul as a port guard ship until early October 1914, when she sailed for Sydney in the company of HMAS Fantome.

[3][6] Protector remained in Australian waters, mainly at Melbourne, until October 1915, when she sailed for the Cocos Islands in the Indian Ocean to report on the wreck of the German cruiser Emden.

In May 1920, she carried the advance party to Flinders Naval depot on Westernport Bay (later renamed HMAS Cerberus Training School) in preparation for the official opening which took place on 1 September 1920.

In June 1924, Protector's 40-year naval career came to a close when she was paid off for disposal and was sold to Mr J. Hill of Melbourne for £677 and 10 shillings.

In the same year, the hulk was purchased by Christian Poulsen for ten pounds, and was subsequently taken to Heron Island off the Queensland coast, where the vessel was sunk for use as a breakwater.

Protector's stern 6-inch (150 mm) breech-loading gun mounting was located at Semaphore's foreshore, a historic seaside suburb of Adelaide, South Australia, for many years.

[13] In 2018, the gun was returned to the Semaphore foreshore following a joint restoration project by the RAN and Le Fevre High School.

[14] A 4-inch (100 mm) QF gun from Protector is on display at the National Military Vehicle Museum in Edinburgh, South Australia.