HMAS Sydney was a light cruiser of the British Modified Leander class. First named as HMS Phaeton when the building started in 1933, the ship was purchased by the Commonwealth of Australia and renamed.
HMAS Sydney served the Australian Navy from 1935 to 1941 when it was sunk during a battle off the Western Australia coast.
Several artifacts from the wreck have been recovered and located in museums and at memorials like this one. A propeller is the centrepiece of the memorial, surrounded by a full list of all the names of the personnel who perished and information about the memorial and HMAS Sydney.
HMAS Sydney Cairn 
is at Quobba, close to the location where the light cruiser was sunk. There is no artifact at the Cairn as it was created nearly 5 years before the wreck was found.
The first action seen by HMAS Sydney was in 1940 after she was ordered to the Mediterranean when World War II broke out. HMAS Sydney was to bombard the Libyan port of Bardia on the 21st of June 1940.
On the 27th June 1940, she went to sea in company with a cruiser squadron to provide convoy cover. HMAS Sydney sunk the Italian Destroyer Espero on the following day, the 28th June.
Shortly afterwards, the HMAS Sydney came under fire again on the 9th of July, then on the 19th July, she entered a tactical battle by engaging and disabling the fast Italian Cruiser, Bartolomeo Colleoni.
HMAS Sydney immediately entered pursuit of another Italian Cruiser. The faster Giovanni Delle Bande Nere was able to get out of range and HMAS Sydney, nearly out of ammunition, gave up the chase of the faster ship.
HMAS Sydney saw further action escorting convoys overseas and participated in convoy escort duties in Western Australia after returning home.
Last visiting Geraldton from 18th to 20th October 1941, HMAS Sydney escorted the Hired Transport Zealandia in the Sundra Straits. After a handover with HMS Durban, HMAS Sydney was returning home when she encountered the HSK Kormoran, a German Raider.
The engagement resulted in both ships being sunk, however, the HMAS Sydney and her crew of 645 personnel were lost completely. 318 of the 399 personnel on the HSK Kormoran survived. The dome over the ship’s propeller is made of 645 stainless steel gulls, representing each of the lost sailors. Seagulls traditionally personify the souls of lost sailors.
The bronze sculpture of a woman at the edge, as shown in the main photo, represents the “Waiting Woman” grieving for her menfolk. Leaning into the wind, she waits anxiously with everlasting empty waiting.
The HMAS Sydney was found in March 2008, at a depth of nearly 2.5km, about 200km off the coast from Steep Point.