Nuestra Señora de Atocha was a Spanish treasure galleon and the most widely known vessel of a fleet of ships that sank in a hurricane off the Florida Keys in 1622. At the time of her sinking, Nuestra Señora de Atocha was heavily laden with copper, silver, gold, tobacco, gems, and indigo from Spanish ports at Cartagena and Porto Bello in New Granada and Havana, bound for Spain. The Nuestra Señora de Atocha was named for the Basilica of Nuestra Señora de Atocha in Madrid, Spain. It was a heavily armed Spanish galleon that served as the almirante for the Spanish fleet. It would trail behind the other ships in the flotilla to prevent an attack from the rear.

A shipwreck is the wreckage of a ship that is located either beached on land or sunken to the bottom of a body of water. Shipwrecking may be intentional or unintentional. There were approximately three million shipwrecks worldwide as of January 1999, according to Angela Croome, a science writer and author who specialized in the history of underwater archaeology.