Acoustic Technologies –
Deep water archaeology: HMAS Australia and M24 midget submarine

In 2002, the NSW Office of Environment and Heritage received notification of the discovery of the wreck of the ex-battlecruiser HMAS Australia. The wreck had been accidentally found in 1990 during a surface side-scan remote sensing survey undertaken by the M/V Moana Wave. The HMAS Australia was the first flagship of the Royal Australian Navy, and the only battlecruiser in the fleet. The presence of this vessel in the region during World War I helped protect Australia from German invasion, and effectively drove the German Imperial Fleet from the Asia Pacific region. On April 12 1924, the vessel was scuttled 50 miles off Sydney Heads as part of an aim to reduce the arms race post-war.

The wreck of a Japanese Type A Ko-Hyoteki two-man midget submarine, known as M24, was located in offshore coastal waters off Sydney in November 2006. The submarine was the third and ‘missing’ midget from the 31 May 1942 attack on Sydney Harbour. Internationally it is one of only five Japanese midget submarine wreck sites located in their unique underwater contexts. Survey operations have confirmed that its two-man crew are likely still contained within the wreck.