High Quality Content by WIKIPEDIA articles! U.S. Naval Base Subic Bay was a major ship-repair, supply, and rest and recreation facility of the United States Navy located in Zambales, Philippines. It was the largest U.S. Navy installation in the Pacific and was the largest overseas military installation of the United States Armed Forces after Clark Air Base in Angeles City was closed in 1991.Subic Bay's famous strategic location, sheltered anchorages, and deep water was first made known when the Spanish explorer Juan de Salcedo reported its existence to the Spanish authorities upon his return to Manila after Salcedo arrived in Zambales to establish the Spanish crown but it would be a number of years before the Spanish would consider establishing a base there.