The 310-year-old wreck was a galleon of the Spanish Navy, known as San Jose, and was sunk by British warships in a battle off the coast of Cartagena, Colombia, in 1708, while carrying gold, silver and emeralds valued at $17billion (£13.49billion). In November 2015, Jeff Kaeli, a research engineer with the Woods Hole Oceanographic Institution, confirmed he had found “the holy grail of shipwrecks” at the bottom of the Caribbean Sea. Bronze cannons engraved with dolphins – a telltale sign of its origin – were spotted thanks to the robot submarine Remus 6000 – which can dive nearly four miles and is equipped with sensors and cameras.
Speaking to CBS in 2018, Mr Kaeli said: “I just sat there for about 10 minutes and smiled.
“I’m not a marine archaeologist but I know what a cannon looks like.
“So at that moment, I guess I was the only person in the world who knew we’d found the shipwreck.”
The Remus 6000, operated by the Woods Hole Oceanographic Institute in Massachusetts, found the ship almost 2,000 feet below the surface.
The exact location of the shipwreck has been kept under wraps after the value of its cargo was confirmed.
The submarine scanned the seafloor using long-range sonar then went back and took pictures of any objects that seemed out of the ordinary.
Working with the Colombian government, the Woods Hole team also found artefacts like teacups and ceramic jugs.
Mr Kaeli added: “You can take bigger risks with your technology and go to places where it wouldn’t be safe or feasible to put a human being.
“Everyone is focused on the treasure aspect, the whole thing is a cultural treasure.
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The galleon’s captain, Jose Fernandez de Santillan, knew that the British – who were involved in the war – might have ships waiting to attack in Cartagena – the city was only meant to be a quick stop.
Gonzalo Zuniga, a curator at the Naval Museum of the Caribbean in Cartagena revealed how the captain pushed on regardless and by the evening of June 8, the Navy – armed with pistols, swords and knives – tried three times to board the galleon and take it as their own.
He told the BBC in 2019: “The San José was winning the battle.
“But, we don’t know what condition the San Jose was in during its last [moments].”
Mr Zuniga’s theory is that instead of surrendering the San Jose and returning to Spain empty-handed, its captain ignited the gunpowder on the ship and exploded the galleon himself.