SYDNEY, Australia — The Endeavour set off from England in 1768 and traversed a world that sailors’ maps had yet to document. The ship bounded through the Pacific Ocean, scraping up against the Great Barrier Reef and stopping in New Zealand and Tahiti. The journey also charted parts of Australia, leading its captain, James Cook, to become regarded as a central figure in the nation’s origin story.

A decade later, the vessel sank after having been sold, renamed (as the Lord Sandwich 2) and scuttled, apparently left to anonymously join about a dozen other ships in a mass grave of wreckage off the coast of Rhode Island.

But marine archaeologists said this week that after a search that spanned decades, the remains of the Endeavour, however decrepit, may have been located. The Rhode Island Marine Archaeology Project said that on Friday it would detail the results of its study of what lies at the bottom of Newport Harbor, and it is expected to announce that it has narrowed down the wreckage that belongs to the storied ship.

“We can say we think we know which one it is,” Kathy Abbass, the archaeology project’s director, told Fairfax Media.