There’s nothing quite as mysterious as a shipwreck filled with gold coins and so much more to explore. Deep beneath the Caribbean Sea lies a legendary treasure that has captivated historians and adventurers for many years, the Spanish galleon San José, often called the “world’s richest shipwreck.”
More than 300 years after meeting its fate and sinking to the bottom of the sea, new explorations using underwater robotics have uncovered gold coins scattered across the wreck, their surfaces bearing the distinctive Jerusalem cross design.
The San José’s Final Voyage
The San José, a 64-gun flagship, departed Portobelo, Panama, on May 28, 1708, carrying treasure harvested from South American mines, such as gold, silver, and emeralds, intended to fund Spain’s embattled King Philip V.
On June 8, as the fleet neared Cartagena, Colombia, it encountered a squadron of British warships under Commodore Charles Wager. In the Battle of Barú, a catastrophic explosion aboard the San José sent the galleon and its spectacular cargo to the seafloor.
The Lives Aboard the Ship
The ship carried precious cargo with nearly 600 people, including sailors, soldiers, officers, and merchants, each with their own stories and families left behind. In a matter of minutes, the explosion that tore through the galleon consigned nearly all aboard to the depths, leaving just 11 survivors to bear witness to the horrors of that fateful night.
The Almost Lost Treasure
This surely was a cargo fit for kings and one of the largest ever hauled across the Atlantic by the Spanish crown. Meticulously packed into wooden chests and sealed barrels were hundreds of thousands of gold and silver coins. Alongside the coins lay dazzling emeralds pried from South American mines, ingots of pure silver, and intricately fashioned jewelry intended for the royal treasury or the nobility of Spain.
“This treasure that sank with the ship included seven million pesos, 116 steel chests full of emeralds, 30 million gold coins,” says Rahim Moloo, the lawyer representing Sea Search Armada.
The Treasure’s Modern Value
Modern estimates place the combined worth of its gold coins, silver bars, and emeralds between $16 billion and $20 billion, making it the most valuable sunken cargo ever discovered. This immense fortune remains largely untouched on the seafloor near Colombia, awaiting resolution of ongoing legal disputes and archaeological plans.
“The galleon was laden with up to 200 tons (180 metric tons) of gold, silver, and uncut gemstones when it sank, and the treasure’s modern value may be as high as $17 billion,” Live Science reported.
Gold Coins Bearing the Jerusalem Cross
These hand-struck, irregularly shaped coins, known as “cobs,” served as the primary currency of Spain’s colonial empire for over two centuries. The cross’s presence on the coins signified Spain’s union of church and state and its far-reaching ambitions across the Atlantic.
“One side has a variation of a Jerusalem cross, one large cross surrounded by four smaller crosses, and a shield decorated with castles and lions. On the back, these coins show the Crowned Pillars of Hercules above the waves of the sea, with the waves being unique to the Lima Mint,” the researchers wrote in the study.
The Lima Mint Connection
These coins have the distinctive “L” mintmark of Lima, Peru, along with the year 1707 and the assayer’s mark, clearly showing that they were struck at one of the most important mints in the Spanish colonial world. The Lima Mint was established to process gold and silver mined throughout Peru’s viceroyalty, producing high-value denominations like the 8-escudo coin, intended for large-scale overseas shipments to fund the empire and war.
The Lima cobs are decorated with the Jerusalem cross on one side and the crowned Pillars of Hercules rising above stylized waves on the other, a signature element of Lima’s gold coinage.
Unearthing History with Robotics
Researchers first pinpointed the legendary wreck in 2015 using the REMUS 6000, an autonomous submersible with high-grade cameras and sonar that can scan the ocean floor at depths up to 1,960 feet. This robotic explorer captured sharp, detailed images confirming the identity of the San José through telltale clues like its bronze cannons and scattered gold coins, while digitally mapping the sprawling debris field in three dimensions.
Confirming the Identity
Findings from the coins’ designs and records confirmed the shipwreck’s identity as the San José, a conclusion lauded by maritime scholars. No other known shipwreck matches these criteria: a treasure fleet flagship lost after 1707 while sailing the Tierra Firme route. Further certainty was gained by identifying signature bronze cannons decorated with engraved dolphins, a unique feature of the San José.
“The finding of cobs created in 1707 at the Lima Mint points to a vessel navigating the Tierra Firme route in the early eighteenth century,” said lead researcher Daniela Vargas Ariza. “The San José Galleon is the only ship that matches these characteristics.”
Legal Battles and Ownership Disputes
nsurprisingly, there will be legal battles over who owns this treasure that was lost for years. The Colombian government asserts sole ownership, designating the wreck as a national cultural asset. However, the U.S. salvage company Sea Search Armada (formerly Glocca Morra) contends it found the wreck in the 1980s and is entitled to a significant share based on prior agreements.
This dispute is being argued before the Permanent Court of Arbitration in The Hague. “It’s a great mess and I see no easy way out of this,” says Carla Rahn Phillips, a historian who has written a book about the San José. “The Spanish state, the Colombian government, the various indigenous groups, the treasure hunters. I don’t think there’s any way that everyone can be satisfied.”
Political Promise and National Heritage
President Gustavo Petro has publicly made the recovery of the ship and its stunning treasure a top priority for his administration, urging his ministers to accelerate the project before his term ends in 2026. The Colombian government claims the San José is an “Asset of National Cultural Interest”.
The Spanish state and indigenous groups from Bolivia and Peru also staked their claim to the loot. “This cargo belongs to our people – the silver, the gold – and we think it should be raised from the sea bed to stop treasure hunters looting it. How many years have gone by? Three hundred years? They owe us that debt,” said Samuel Flores, a representative of the Qhara Qhara people, one of the indigenous groups.
Archaeological Preservation over Exploitation
Colombian authorities have officially designated the San José site as a “protected archaeological area,” emphasizing that its actual value lies in scientific research and cultural legacy rather than in its glittering wealth. The plan is to conserve artifacts for public display in a dedicated museum and develop conservation laboratories, ensuring that the site’s historical, human, and material stories are studied and shared, not scattered or sold.
“The treasure of the San José should remain at the bottom of the sea, along with the human remains of the 600 crew members who died there,” said Juan Guillermo Martín, a Colombian maritime archaeologist. “The treasure is part of the archaeological context, and as such has no commercial value. Its value is strictly scientific.”
Ongoing Underwater Surveys
Since 2024, Colombian-led teams have systematically deployed remotely operated vehicles (ROVs) and deep-sea imaging technologies to noninvasively document the entire wreck site, which is now officially protected as an archaeological area.
Photogrammetric mapping has enabled researchers to reconstruct wreck sections in 3D with unprecedented precision, while careful surveying ensures no artifacts are removed until the site is thoroughly understood and catalogued. Officials stress that ongoing surveys represent only the first step in a multi-year plan to study, conserve, and eventually showcase this remarkable treasure.
Plans for a Museum and International Collaboration
The Colombian government has embarked on an ambitious plan to establish a state-of-the-art museum in Cartagena to preserve and showcase the treasures and history of the San José shipwreck. This museum is envisioned not just as a display of gold and artifacts but also as a center for scientific study and public education on maritime heritage.
Partnerships have been forged with global experts, research institutions such as Woods Hole Oceanographic Institution, and advisory bodies under UNESCO’s Convention on the Protection of the Underwater Cultural Heritage. These alliances bring advanced technology and expertise in underwater archaeology, while also underscoring the commitment to make the San José’s legacy a shared global heritage.
The Enduring Mystery
As legal challenges swirl and further exploration continues, new chapters of the San José story are bound to unfold. Varying eyewitness testimonies from the scant survivors add layers of intrigue, sometimes conflicting with archaeological evidence.
Recent underwater surveys have expanded the list of unexplored shipwrecks nearby, raising questions about possible confusion or undiscovered secrets linked to the San José and its historical context.
