Queensland State Archives posted a photo:
The steam dredge Platypus was built in 1883 by William Simons & Co Ltd at Renfrew, Scotland for the Queensland Government. For more than 40 years she dredged shipping channels in ports along the Queensland coast. In 1926 she was put into the dry dock at South Brisbane (now the Queensland Maritime Museum) to be stripped of useful equipment. On 21 October 1926 the hulk was then sunk as a breakwater off Peel Island in Moreton Bay, where she still lies today.
Queensland State Archives Item ID972528, Photographic material