H.M.A.S. Sydney I Memorial Mast is dedicated to those who served in the Royal Australian Navy and those ships which were lost in service. The mast was restored and rededicated on the 2nd October 2013.
In 1934 the Mayor of Mosman purchased the mast (at Commonwealth expense) and erected it astride the nationally significant 1839 defence fortifications at Bradleys Head as a memorial to those who died in the Emden action. The idea for the installation of the mast came from local resident Norman Ellison, who proposed its dedication coincide with a visit by the Duke of Gloucester in November 1934.
On Thursday 12th November 1964 the HMAS Sydney I mast was dedicated as an official memorial to the memory of those who served in the Royal Australian Navy (RAN) and the nineteen naval ships lost in service. On 26 June 2007 the Royal Australian Navy announced that a new naval tradition would commence that day requiring all Australian and foreign naval vessels proceeding into Sydney Harbour to render ceremonial honours to the HMAS Sydney I Memorial Mast. The ceremony consists of bringing the ship's company on the upper decks to attention, and then 'piping' the Mast.