The hull remains of the so-called Black Rock ship are measured and compared to the dimensions of known shipwrecks off East Caicos. Through a process of elimination, an archaeological team was able to rule out all of the ships except the Spanish slave ship Trouvadore, which sank in the Caribbean in 1841.
Some 192 Africans survived the sinking of the Spanish ship Trouvadore off the British-ruled islands, where the slave trade was banned.
Over the years the ship had been forgotten, said researcher Don Keith, so when the discovery connected the ship to current residents the first response "was a kind of shock, a lack of comprehension," he explained in a briefing organized by the U.S. National Oceanic and Atmospheric Administration.
But after word got out "people really got on board with it," he said, and the local museum has assisted the researchers. He said this is the only known wreck of a ship engaged in the illegal slave trade.
Keith and his co-researchers from the Texas-based Ships of Discovery organization came across a letter at the Smithsonian Institution that referred to the sinking and began their search for the ship.
"The people of the Turks and Caicos have a direct line to this dramatic, historic event -- it's how so many of them ended up being there. We hope this discovery will encourage the people of the Turks and Caicos to protect and research their local history, especially the history that remains underwater," he said.
"It really is a mystery, it's a detective story," added marine archaeologist Toni Carrell.
"We do all of this because we recognize the importance of history. This is an important part of the Turks and Caicos history," she said.
The team was able to determine that authorities on the islands apprenticed the Africans to trades for a year and then allowed them to settle on the islands, many on Grand Turk. The Spanish crew was arrested and turned over to authorities in Cuba, then a Spanish colony.
An 1878 letter refers to the Trouvadore Africans as making up the pith -- meaning an essential part -- of the laboring population on the islands.
When the wreck was first discovered in 2004 it was named the Black Rock ship because the researchers were unsure of its identity. They have since become convinced by the timing and design of the vessel that it is the Trouvadore.
"We were not fortunate enough to find a bell with 'Trouvadore' on it," Carrell said. Useful parts of the ship had been salvaged before winds and currents carried it into deeper water.
"It's rare and exciting to find a wreck of such importance that has been forgotten for so many years," said Frank Cantelas, marine archaeologist for NOAA's Office of Ocean Exploration and Research.