The Black Swan Project is the project name given by Odyssey Marine Exploration for its discovery and recovery of an estimated US$500 million worth of silver and gold coins from the ocean floor. Initially Odyssey kept the origin of the treasure confidential. It was later proved in trial that the recovered cargo was being carried by the Spanish frigate Nuestra Señora de las Mercedes, which was sunk by the British Royal Navy off Portugal in 1804.

Nuestra Señora de las Mercedes was a Spanish Navy frigate which was sunk by the British off the south coast of Portugal on 5 October 1804 during the Battle of Cape Santa Maria.