In the spring of 1708 Charles Wager was on an expedition in the Caribbean with a squadron of four ships :
In April the squadron took in supplies on the small island of Pequeña Barú , today called Isla El Rosario, just 30 miles away from Cartagena. Hereby the Spanish were aware of their presence and the governor of Cartagena send warnings to the Spanish fleet, which was anchored in Portobelo.
Nevertheless, the commander of the treasure fleet José Fernández de Santillán ,decided to sail from Portobelo to Cartagena on May 28. He couldn't wait much longer, because the hurricane season was approaching and the rest of the fleet, plus their escort under Jean Du Casse, were waiting in Havana, and threatened to leave without him.
The Spanish fleet was composed of eleven merchant ships (some armed), and seven escorting warships :
The gold and silver was concentrated on the 3 largest vessels. The San José had 7 to 11 million pesos on board, and the San Joaquin 5 million. The Santa Cruz had the rest, only a fraction of the other two ships.
The Spanish fleet reached Isla de Baru on the evening of June 7 and anchored there. The next day there was very little wind, but around 3 p.m. they noticed Wager's squadron approaching. The Spanish took up defensive positions but the English knew they had to attack the largest ships, because they had the most money onboard.
The Kingston attacked the San Joaquin around 5 p.m. which, after two hours of battle , escaped into the night with the help of the Concepción.
The Expedition attacked the San José and approached the vessel with the clear intention of boarding the ship. Around 7 p.m., after an hour and a half of fierce fighting and with only 60 meters between the two ships, suddenly the San José blew up. The ship sank immediately, taking its precious cargo and the entire crew to the bottom of the sea. There were only 11 survivors out of the 600 crew and passengers onboard.
By now it was dark, but there was a full moon and Wager succeeded in finding the Santa Cruz at 2 a.m. After a brief fight, which left 14 English and 90 Spanish dead, the Santa Cruz was taken; however, she had no government treasure in her - only 13 chests of pieces-of-eight and 14 pigs of silver which seem to have been private property.
At dawn, the English discovered the San Joaquin, and Wager ordered the Kingston and Portland to capture the ship. The San Joaquin could escape into the Cartagena harbour after some salvos, and the English dared not follow and face the guns of the Cartagena forts.
The rest of the Spanish fleet also reached Cartagena safely, with the exception of the Concepción which , cornered by the English, beached itself on Baru Island and set the ship alight.
The English had eliminated three Spanish ships and prevented the gold and silver to cross the sea and fund the Franco-Spanish war effort.
But Charles Wager was disappointed with the loot, which would make him a rich man, but which could have been many times larger if they had captured the San Joaquin.
Captains Bridge and Windsor were expelled from the Navy for this.
The treasure of the San José is still on the bottom of the ocean. It is estimated to be worth between $150 and $450 million US dollars based on the speculation that it likely had seven to 10 million Spanish pesos on board at the time of its sinking, similar to its surviving sister ship, the San Joaquin. The San José is called the "Holy Grail of Shipwrecks" and is actively being pursued by treasure hunters today. A group of investors operating under the name Sea Search Armada claim to have found the ship off the coast of Colombia, but the Colombian government has not been able to verify its existence at the stated coordinates. A legal dispute over the rights to the treasure was resolved in July 2007 when the Colombian Supreme Court concluded that any treasure recovered would be split equally between the Colombian government and the explorers. Other individuals claim to have found the wreck in other places, leaving its true location a mystery.