As early as 1566, the Spanish began sending annual treasure fleets from their holdings in the New World to Spain, consisting of galleons in well-armed fleets or armadas. One of the armada routes ran from Cartagena in present-day Colombia and Portobello in present-day Panama to Havana, Cuba, where they would rendezvous with another fleet from Veracruz in Mexico. The 1622 voyage of the treasure ship Neustra Señora de Atocha (“Our Lady of Atocha”—named for a church in Madrid) was delayed by loading the immense treasure that had been packed over the Isthmus of Panama for shipment from Portobello. Eventually a 28-ship convoy of galleons and auxiliary vessels sailed for Spain from Havana on September 4, 1622. Even then mariners knew very well that the storm season for the Caribbean and the Gulf of Mexico begins in mid- or late August and continues into the fall months, but the fleet sailed anyway.
Two days and about 50 miles out of Havana, off the Dry Tortugas, the 1622 armada was struck by a hurricane, driving the Atocha and a sister ship, the Santa Margarita, onto coral reefs. The ships sank in relatively shallow waters, with the Atocha going down some 55 feet. The Spanish never located the exact spot ofthe loss of Atocha, but spent ten years salvaging about half of the cargo of the Santa Margarita. With the equipment available at the time, salvage was difficult, made harder by further storms scattering wreckage and cargoes. The Spanish used a primitive diving bell, but the workers, mostly slaves, often died from decompression or drowning.