Marine archaeologists believe they have found the ship of legendary explorer Captain James Cook — the one he used to “discover” Australia’s East Coast- off Rhode Island in Newport Harbor.

The Rhode Island Marine Archaeology Project will announce on Wednesday that it has likely located the HMS Endeavour — later known as the Lord Sandwich — one of 13 sunken ships lost when Newport was under siege in 1778, days before the Battle of Rhode Island during the American Revolution, as Washington Post reports.

Marine archaeologists say they are now “closing in one of the most important shipwrecks in world history”.

Researchers with the Rhode Island Marine Archaeology Project, a nonprofit organization that studies maritime history and marine archeology sites, used historic documents in London to map out and analyze sites where the ship might be found on the sea floor.

Recent data analysis shows that there is an 80 to 100 per cent chance the ship is still in the harbour.