A replica of Captain Cook's ship Endeavour at the Australian National Maritime Museum in Sydney on Wednesday. (Saeed Khan/AFP/Getty Images) (SAEED KHAN/AFP/Getty Images)

More than two centuries ago, the British Royal Navy purchased a 4-year-old merchant ship with a flat-bottomed hull that was ideal for transporting cargo. The year was 1768. To the west, across the Atlantic Ocean, unrest was brewing among a group of British colonies — but the Royal Navy’s newest acquisition was intended for decidedly scientific purposes.

The vessel would embark on an expedition to take British researchers to the South Pacific, with two goals: To observe Venus crossing the sun and to search for a continent called “Terra Australis Incognita,” better known now as Australia. The Royal Navy spent weeks refitting the ship and soon renamed it the HMB Endeavour, a moniker suitable for its epic journey to come.

A 39-year-old naval officer and cartographer named James Cook was put in command of the Endeavour and, in August of 1768, the explorer and his crew set sail from Plymouth, England, on what would become the first of Cook’s famed Pacific voyages.

For weeks, Cook and the Endeavour made their way slowly toward the Pacific, pushing south and west until they had cleared Cape Horn, at the southernmost tip of South America. They made it to Tahiti in April 1769, in time to document the Venus transit, and pressed on, mapping and exploring New Zealand and various Pacific islands along the way. A year later, they landed on the eastern coast of Australia.

The trip left the Endeavour in poor shape, the more so after the ship ran aground on a portion of the Great Barrier Reef. Cook and his crew were forced to spend seven weeks docked on this foreign continent to repair the vessel but eventually were able to continue westward. Remarkably, the Endeavour rounded the Cape of Good Hope, on the southern tip of Africa, and made its way back to the British-occupied island of Saint Helena, nearly three years after it had departed England.

Cook — and the HMB Endeavour — had successfully circumnavigated the globe.

The expedition brought fame and acclaim to Cook, who would go on to explore the Pacific twice more, on a different ship, until he was killed in the Hawaiian islands in 1779. The Endeavour, however, faded from glory. The ship was refitted again and used for routine naval trips to the Falkland Islands. In 1775, His Majesty’s Bark Endeavour was sold to a private owner and given the far less evocative name “Lord Sandwich II.”

With the Revolutionary War underway, the Lord Sandwich was next used to transport British troops to North America. It joined about a dozen other British ships anchored in Newport Harbor, off Rhode Island, until a French fleet — outfitted with bigger guns — threatened to overrun the harbor in 1778.

The British “decided that the best plan would be to scuttle their vessels and try to create a blockade around Newport so that the French ships couldn’t sail in because they would get hung up on the sunken vessels,” Brown University researcher Carolyn Frank told the Jamestown Press in 2012. “They took everything off of the ships and sunk them right before the Battle of Newport.”

The once-legendary ship hasn’t been seen since.

Those who have long sought the Endeavour’s remains hope that will soon not be the case. More than two centuries later, researchers say they believe they have pinpointed the ship’s final resting place, according to the Rhode Island Marine Archaeology Project (RIMAP).

The nonprofit has spent more than 25 years searching for the Endeavour, as well as dozens of other vessels lost off the coast of the state during the American Revolution. Over the years, RIMAP has whittled down possible locations for the ship’s remains.

This week, the group announced it would reveal Friday “the details of a promising candidate to be that iconic ship,” just off Goat Island in Narragansett Bay.

“We can say we think we know which one it is,” RIMAP Director Kathy Abbass told Fairfax Media. “It is exciting. We are closing in. This is a vessel that is significant to people around the world, including Australia.”

In a statement, Abbass said the group has, over the years, methodically narrowed the search for the Endeavour from among the 13 British vessels sunk in 1778 to five, “possibly to one or two archaeological sites.”

“Now that [we] have identified a possible site in Newport Harbor that might be the Lord Sandwich ex Endeavour, the detailed work must begin to prove it,” the group said in an appeal for donations to fund the excavation.

The Endeavour has arguably never been forgotten, however. Docked in the waters at the Australian National Maritime Museum in Sydney is a faithful replica of the HMB Endeavour as it probably existed in Cook’s day, complete with clothes hung out to dry.

And nearly 200 years after Cook explored the Pacific, NASA named the space shuttle Endeavour after the historic vessel; a wooden piece from the original ship was reportedly in the cockpit of the shuttle when it was blasted into space.

Still, nothing is a substitute for the real thing. The group noted that this year is the 250th anniversary of Cook’s departure on the Endeavour to the Pacific — and that 2020 will be the same anniversary of the explorer claiming Australia for Britain.

“The identification of the Lord Sandwich ex Endeavour in Newport Harbor will be particularly significant during this time of historical celebrations,” the group said.

Correction: An earlier version of this story incorrectly stated the Cape of Good Hope is the southernmost tip of Africa. It is on the southern tip of the continent but Cape Agulhas is the southernmost point of Africa.

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