San Diego was a Spanish merchant vessel converted into a warship to battle with the Dutch ship Mauritius on December 14, 1600. San Diego sank off the waters of Nasugbu, Batangas Province, southwestern Luzon, about a kilometer from Fortune Island. The survey and excavation of this shipwreck was a seminal undertaking between the National Museum of the Philippines and the World Wide First Inc. (WWF) that resulted in the recovery of more than 34,000 archaeological objects, providing a treasure trove of information on the Philippine’s maritime culture during that period.

Antonio de Morga was the lieutenant-general of the Philippine governor and was appointed commander of the Spanish fleet that was hurriedly organized to combat Dutch intruders into Manila Bay. De Morga was the captain of the flagship San Diego while captain Olivier Van Noort commanded the Dutch flagship Mauritius. The two ships engaged in battle for several hours until San Diego was defeated and sunk in Batangas waters. Both captains survived to write separate accounts of the battle.

Almost 400 years later, a shipwreck was found 1.2 kilometers off Fortune Island, more than 50 meters below sea level, buried under up to three meters of sediment and debris.