<P> The first contact of European navigators with the western edge of the Pacific Ocean was made by the Portuguese expeditions of António de Abreu and Francisco Serrão, via the Lesser Sunda Islands, to the Maluku Islands, in 1512, and with Jorge Álvares's expedition to southern China in 1513, both ordered by Afonso de Albuquerque from Malacca . </P> <P> The east side of the ocean was discovered by Spanish explorer Vasco Núñez de Balboa in 1513 after his expedition crossed the Isthmus of Panama and reached a new ocean . He named it Mar del Sur (literally, "Sea of the South" or "South Sea") because the ocean was to the south of the coast of the isthmus where he first observed the Pacific . </P> <P> Later, Portuguese explorer Ferdinand Magellan sailed the Pacific East to West on a Castilian (Spanish) expedition of world circumnavigation starting in 1519 . Magellan called the ocean Pacífico (or "Pacific" meaning, "peaceful") because, after sailing through the stormy seas off Cape Horn, the expedition found calm waters . The ocean was often called the Sea of Magellan in his honor until the eighteenth century . Although Magellan himself died in the Philippines in 1521, Spanish Basque navigator Juan Sebastián Elcano led the expedition back to Spain across the Indian Ocean and round the Cape of Good Hope, completing the first world circumnavigation in a single expedition in 1522 . Sailing around and east of the Moluccas, between 1525 and 1527, Portuguese expeditions discovered the Caroline Islands, the Aru Islands, and Papua New Guinea . In 1542--43 the Portuguese also reached Japan . </P> <P> In 1564, five Spanish ships consisting of 379 explorers crossed the ocean from Mexico led by Miguel López de Legazpi and sailed to the Philippines and Mariana Islands . For the remainder of the 16th century, Spanish influence was paramount, with ships sailing from Mexico and Peru across the Pacific Ocean to the Philippines via Guam, and establishing the Spanish East Indies . The Manila galleons operated for two and a half centuries linking Manila and Acapulco, in one of the longest trade routes in history . Spanish expeditions also discovered Tuvalu, the Marquesas, the Cook Islands, the Solomon Islands, and the Admiralty Islands in the South Pacific . </P>

What sea is part of the south pacific