Debated. Stone tools were found under the sea, but the page only guesses that they are the first of their kind.
Divers recorded 269 stone tools at Cape Bruguieres, off the Pilbara coast of Western Australia, near the Burrup Peninsula. A second underwater site in the same island group also held tools. This coast went under the sea between about 7,000 and 18,000 years ago, after the last ice age, when the sea rose about 130 metres.
The page says these places are not automatically protected, and a planned gas pipeline has raised a fight about keeping such sites safe.
https://www.ancient-origins.net/news-history-archaeology/underwater-aboriginal-sites-0013930