A shipwreck found on the sea floor north of Port Macquarie has been confirmed as the remnants of a vessel that sank in stormy conditions - and left more than 20 people dead - after it departed Newcastle for Townsville 55 years ago.
The national science agency CSIRO on Thursday announced the results of extensive testing which showed the wreck was MV Noongah, a 71-metre coastal freighter that set off from the Hunter with a load of steel in August 1969.
The tragedy killed 21 of the 26 crew members on board - only one of the bodies was recovered.
The disappearance of the ship was Australia's worst post-war maritime disaster and sparked one of the largest-scale searches in the nation's history - involving navy and merchant vessels, aircraft, and shore-based efforts along beaches.
MV Noongah's final resting place remained a mystery for more than half a century, until a collaborative project involving CSIRO, Heritage NSW, and The Sydney Project began investigating possible locations.
CSIRO research vessel Investigator took a crew to a spot between Port Macquarie and Coffs Harbour in June, where high resolution sea floor mapping data (bathymetry) was collected along with video footage of an unidentified wreck.
Voyage manager Margot Hind said the wreck was sitting upright on the sea floor and was largely intact.
"We were lucky to have favourable sea conditions for the survey and our CSIRO technical teams were able to gather excellent bathymetry and drop camera vision of the wreck," she said.
"The bathymetry data shows the wreck is sitting at a depth of 170 metres and is approximately 71 metres long, with the vessel dimensions, profile and configuration matching MV Noongah."
CSIRO marine expert Matt Kimber, who informed key stakeholders of the survey outcomes, said those conversations offered a poignant reminder of the significance of such maritime heritage discoveries.
"This tragedy is still very much in the memory of many in the community and we offer our condolences to families and descendants of the crew who were lost," Mr Kimber said.
"Our thoughts are also with the surviving crew members from MV Noongah, and we hope that knowing the resting place of the vessel brings some closure for all."
Samir Alhafith, from The Sydney Project, said the discovery was 20 years in the making but it was only recently that technology and diving knowledge allowed wrecks at such depths to be more easily identified.
"Not only is the discovery of these significant wrecks important for the surviving sailors and families of those that perished during the tragedy but also it allows us to investigate the mystery behind the sinking," Mr Alhafith said.
"We would like to express our gratitude to the founders of the wreck, Paul and James Wright, and to Heritage NSW and CSIRO for their assistance to identify the wreck as the Noongah. These collaborations are more important than ever when dealing with challenging deep sites."
Family members and descendants of MV Noongah crew can contact CSIRO for further details about the investigation.