In September of 1622, the Spanish galleon Nuestra Señora de Atocha set sail from Havana carrying a fortune in silver, gold, emeralds, pearls, and goods that represented the wealth of an empire. She was the rear guard of the treasure fleet, armed with twenty bronze cannons and built to protect the convoy from attack. Her holds were so full that the registered cargo alone would be worth hundreds of millions in today’s dollars.

But the fleet left late in the season, and only a day out of Havana the Atocha was caught in a hurricane. She struck the reefs of the Florida Keys and went down in fifty-five feet of water, taking nearly everyone aboard with her. For more than three centuries her treasure was lost until a modern adventurer named Mel Fisher set out to find her. His discovery made history.