The annual Spanish Treasure Fleets were convoys of Spanish warships that departed the country's New World ports – such as Havana, Cuba, in the Caribbean – after receiving mule loads of trade goods such as gold, silver, and jewels from South American colonies like Peru, and were destined for the ports of Cádiz and Seville, Spain.
The Treasure Fleets were notably susceptible to tropical storms. Several fleets in 1622, 1715, 1733, and 1750 were all decimated by hurricanes, spilling a fortune of gold reales into the ocean.
In July 13, 1715, a fleet under the command of Captain-General Don Juan Esteban de Ubilla left Havana. Six days after their departure from Havana, the Treasure Fleet was hit by a severe hurricane, which destroyed eleven of its twelve vessels. The surviving ship was a brig known as El Dorado, which had been stolen by the pirates Edward Kenway and Adéwalé during their escape from imprisonment aboard one of the fleet's sister ships. Following the escape, Kenway took the El Dorado as his own and rechristened it the Jackdaw.
Word of the fleet's capsize quickly spread throughout the region, with wild variances on the details; Edward Thatch at one point expressed an interest in diving the wrecks. Edward Kenway, on the other hand, dove to the wreck of the San Ignacio to locate medicines for the citizens of Nassau, although the cures he recovered were "quite spoilt".
In November 1716, another Spanish Treasure Fleet was attacked by the pirates Alonzo Batilla, Olivier Levasseur and Samuel Bellamy; upon noticing the pirates, the fleet made to depart, though Alonzo Batilla pursued and engaged them. Despite this, Alonzo could not find Samuel Bellamy's "treasure", which proved to be a Fragment of Eden. Of the fleet's six ships, one frigate survived the conflict, though the pirates were forced to leave it after being confronted by Francis Hume.