Once again, despite recent news claims that Captain Cook's H.M.B. Endeavour has been found, it still actually remains undiscovered. According to a press release from the Rhode Island Marine Archaeology Project, they have narrowed the search for the ship to “possibly to one or two archaeological sites” that will be excavated in 2019. Previous claims that the H.M.B. Endeavour may have been found were made in 1999, 2002, 2006, 2012, and 2016. This story was originally published on May 4, 2016.

In the leadup to a press conference held Wednesday in Providence, Rhode Island, news headlines around the world were announcing the possible discovery of the H.M.B. Endeavour, made famous when Captain James Cook sailed it around the world in the later 18th century, charting the east coast of Australia for the first time.

However, according to data presented by the Rhode Island Marine Archaeology Project (RIMAP), a non-profit organization that presented their research at the press conference and is heading up the search for the wreck, the remains of the Endeavour have yet to be located or identified. Here's what we know:

The Endeavour is most likely in Newport Harbor.

Captain Cook commanded the British Royal Navy bark Endeavour on his first circumnavigation of the globe between 1768 and 1771. According to archival research by RIMAP's executive director and principal investigator D.K. Abbass, it was sold into private ownership by the Crown in 1775 and renamed Lord Sandwich.

During the Revolutionary War, Lord Sandwich was chartered as a transport vessel by the British Navy and eventually served as a prison ship for American loyalists in Newport.

The possibility that the remains of the Lord Sandwich (ex-Endeavour) are in Newport Harbor was first publicized in 1999, and its potential discovery has been the subject of several news articles in the years since.

The ship was deliberately sunk in the harbor.

As the Revolutionary War raged in the summer of 1778, a French fleet sailed toward Newport to join up with American forces. The British Navy began to scuttle vessels in the outer harbor to obstruct the French approach. Along with Navy warships, 13 chartered transport vessels were also scuttled, including Lord Sandwich.

Researchers are narrowing down their search for the ship.

RIMAP's team of volunteers has been working on identifying the 13 scuttled transport vessels in Newport Harbor since the late 1990s, locating and mapping nine so far.

In January of this year, Abbass found a document in the British National Archives that indicates Lord Sandwich was among a group five vessels scuttled in a very specific area of the harbor.

RIMAP has located and mapped four Revolutionary War-era vessels in this specific area, and has a remote-sensing "target" that indicates there may likely be a fifth wreck as well.

"We're closing in it," says Abbass. "If we hadn't found that document we'd still be saying it's one of 13 [wrecks] or one of nine. Now we can say its one of five."

However, divers have not yet visited the target to verify that it is indeed a shipwreck and if so, if it's from the right period in history.

No ship in the harbor has been identified as the Lord Sandwich (ex-Endeavour).

We can't rule out the possibility that one of the vessels located in this specific area is indeed Lord Sandwich, but a lot of analysis will be necessary in order to make a firm identification. Researchers will have to find evidence consistent with the vessel being Lord Sandwich (for instance, artifacts associated with its use as a prison ship) and construction details consistent with what's known about the Endeavour.

In addition, they'll have to ensure that no other vessel found in the area can make the same claim. "This is science. You're not sure until you can prove it," says Abbass.

This effort requires a laboratory in which to store and analyze artifacts. RIMAP is currently raising money to build a lab.

Rhode Island is "Shipwreck Heaven."

The state has more shipwrecks per square mile than any other state in the nation, and Narragansett Bay, which includes Newport Harbor, has the highest concentration of Revolutionary War shipwrecks in the world, says Robert Doane, curator of the Naval War College Museum in Newport.

Oddly enough, another of Cook's ships may also be in Newport.

In addition to the Endeavour, some researchers believe that the H.M.S. Resolution, a vessel used in Cook's second and third voyages, also ended up in Newport Harbor after being sold by the Crown. Renamed La Liberte and carrying a cargo of whale oil, the vessel ran aground and was abandoned in 1793.

In the 19th century, remains of La Liberte were touted as the Endeavour and sold off for a time as souvenirs; what was left of the vessel now lies somewhere under modern Newport.