The ship that Captain Cook commanded on his first voyage across the Pacific Ocean may be resting on the seabed off the coast of New England, US.
A modern replica of Captain Cook's famous ship Endeavour
Marine archaeologists believe it is one of four shipwrecks found during an underwater survey of Newport Harbor.
Cook sailed in the Endeavour from 1768-71, exploring the east coast of Australia and claiming it for Britain.
The ship is thought to have ended its days in a 13-strong fleet sunk by British forces off Newport in 1778.
Four of the ships were discovered in August 2005 by Professor Rod Mather of the University of Rhode Island and graduate student Jamin Wells.
"As is the case with many 18th Century shipwrecks, the newly discovered vessels were pinned to the bottom of Newport Harbor with their own ballast stones," said Mather.
"Over time, a complex series of biological, chemical and physical processes broke down the shipwrecks, leaving ballast piles onto which artefacts including cannons fell and below which there is almost certainly well-preserved sections of the ships' lower hulls."
Experts believe the ships were sunk by the British as a French fleet sailed into the bay to act as a barrier against attack. Among them was the Lord Sandwich, which had originally been called the Endeavour.
Two other shipwrecks have previously been discovered in Newport Harbor, bringing the total to six. Archaeologists believe they will soon discover the remains of the other seven ships.
Although several artefacts have been found on the seafloor - including a cannon, an anchor and part of a British teapot - there is nothing to establish a direct link with Cook's Endeavour.
But the researchers are confident they know enough about the ship to eventually identify her.
They plan to excavate the vessels which are lying beneath 6m (20ft) of water about 91m (300ft) from the shoreline.
The upper parts of the ships have rotted away but the keels have been preserved in silt and could contain textiles and leather.