M24 was one of three Japanese midget submarines to enter Sydney Harbour in 1942 and is the only submarine remaining where it sank more than 75 years ago.
A high-resolution digital 3D model has been created of the submarine. The model provides accurate detail of the site and shows what the submarine looks like below sea level.
The site is not a public diving site as it is still the grave of the two Japanese submariners who died on their mission.
Environment Minister Gabrielle Upton said there are many challenges in the ongoing protection of the site.
“We now have a high-resolution baseline recording that will enable maritime archaeologists to monitor changes in the wreck over time,” Ms Upton said.
“Early last year the first public divers were allowed to respectfully explore the site, but not everyone has the specialist diver training to do this.”
The midget submarine is internationally significant and its management by the NSW Government is recognised by UNESCO as world’s best practice.