Archaeologist Paul Tacon says there are telling signs it is a depiction of a Perahu – a boat popular in Indonesia and Malaysia around the 17th century.
“One of the distinctive features is a tripod mast, another is a rectangular sail. And those are quite clear in this image,” he said.
He says beeswax pellets stuck to the painting have been dated back to the 1620s, making it the oldest dated picture of early contact in Australia.
He also says there is clear evidence Macassars from Indonesia were sailing to north Australia to fish for trepang in the 1700s.
The painting is forcing archaeologists to rethink when outsiders first arrived on Australian shores.
“This find is extremely significant because it is our oldest reliably dated contact rock art image,” Mr Tacon said.