One of the largest vessels scuttled on the Long Reef Wreck Site is the bucket dredge Coolooli. Built in 1955 at the NSW Government State Dockyard at Newcastle (NSW), the Coolooli was unpowered. She displaced 150 tonnes and was 50 metres long and 10 or 11 metres wide. The dredge was owned by the NSW Maritime Services Board and used to keep NSW ports navigable. I have read that she dug out Darling Harbour, not sure which part this may have been, but as there have been ships using Darling Harbour for over 100 years, may be it was deepening it.