HMAS Sirius was decommissioned from the Royal Australian Navy on December 18 after more than 15 years' dedicated service providing fuel and stores to ships at sea.

The farewell ceremony at her home port, Fleet Base West, was attended by families and former crew members.

Sirius sailed more than 469,000 nautical miles and conducted more than 770 replenishments at sea during her service.

Chief of Navy Vice Admiral Mike Noonan said the ship and crew made a valuable contribution to Navy operations and exercises since being commissioned on September 16, 2006.

"Sirius and the ship's company lived up to the ship's motto 'to serve and provide'," Vice Admiral Noonan said.

"They faithfully served the fleet, our allies and friends by providing essential fuel, stores and ammunition to ships underway, allowing them to remain at sea for longer.

"While Sirius has served Navy with distinction, the advanced, purpose-built auxiliary oiler replenishment ships Supply and Stalwart will continue to provide a critical support element to Australia's maritime operations."

Commanding Officer Sirius Commander Christopher Doherty, front, centre, and the ship's company at the decommissioning ceremony at Fleet Base West. Photo: Leading Seaman Ernesto Sanchez

Sirius was built as the commercial tanker MV Delos at the Hyundai Mipo Dockyard in South Korea and was purchased by the Australian Government in June 2004.

Following Delos' delivery to Navy, replenishment-at-sea rigs and an enhanced naval communications suite were installed, and the accommodation quarters were modified to house a crew of up to 70.

Sirius conducted her first replenishment on October 25, 2006, with the Anzac-class frigate HMAS Toowoomba, and the last on December 1 this year with HMAS Parramatta.

Commanding Officer Sirius Commander Christopher Doherty said the ship enabled Navy to significantly extend operational reach and endurance at sea.

"Sirius has been a dependable service station and warehouse at sea, day and night, for more than 15 years," Commander Doherty said.

"With careful coordination and communication, Sirius could replenish two ships at once, or one ship and one vertical replenishment by helicopter."

Sirius regularly took part in exercises in Australian waters and while deployed overseas, including Exercise Talisman Sabre, Exercise Kakadu and RIMPAC.

In 2008, the ship formed part of the Great White Fleet Centenary Voyage Task Group to mark 100 years since the visit of the US Navy's Great White Fleet to Australia,

The ship's final deployment was to Southeast Asia and the southwest Pacific, which included a visit to Norfolk Island.

Upon decommissioning, Sirius was transferred to the Capability and Support Group.

More photos can be viewed on the Defence image gallery.