Indigenous Australians have been in Australia for at least 40,000* years and most likely much, much longer. In the last glacial maximum, about 20-25,000 years ago, sea level was about 140 m lower than it is today (current levels stabilised about 6,000 years ago) which meant that Australia was much bigger and what were coastlines are now well and truly submerged. Assuming there were Aboriginal communities and activities along the coast line, there must be many interesting and significant Aboriginal sites that are now under water. I wonder if they have been preserved? Is there such a thing as scuba archaeology?
*I’ve used really rough numbers in this post.