More than two centuries ago, the British Royal Navy purchased a four-year-old merchant ship with a flat-bottomed hull that was ideal for transporting cargo. Across the Atlantic, unrest was brewing among a group of British colonies — but the Royal Navy’s acquisition was intended for 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,” 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 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, they 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 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 a portion of the Great Barrier Reef. Cook and his crew were forced to spend seven weeks docked for repairs. Eventually, they were able to continue westward and the Endeavour 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 circumnavigated the globe.

The expedition brought fame and acclaim to Cook. The Endeavour, however, faded from glory. The ship was refitted again and used for routine naval trips to the Falkland Islands. In 1775, Endeavour was sold to a private owner and renamed the far less evocative “Lord Sandwich II.”

With the Revolutionary War underway, the Lord Sandwich was 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 overtake the harbor in 1778.

The British “decided that the best plan would be to scuttle their vessels and try to create a blockade,” Brown University researcher Carolyn Frank said in 2012.

The ship hasn’t been seen since. But more than two centuries later, researchers believe they have pinpointed the ship’s final resting place and will reveal “details of a promising candidate” on Friday, said the Rhode Island Marine Archaeology Project. The group noted this year is the 250th anniversary of Cook’s departure on the Endeavour to the Pacific.