Pacific North Equatorial Current

North of the equator, the trade winds drive a broad westward movement of Pacific surface water. For sailing vessels leaving the American coast for Asia, this combination of wind and current helped make a long westward passage practicable. Spanish ships sailing from New Spain toward the Philippines used the tropical Pacific as part of the maritime system that connected American silver with the commercial world of Manila.

The sea was already travelled by the peoples of Micronesia and neighbouring island groups. Navigators learned to recognise stars, swells, cloud formations, and the behaviour of birds, combining observation with knowledge transmitted through teaching and experience. Their voyages linked islands across extensive maritime networks. Ocean crossings required careful preparation: drinking water, preserved food, sound vessels, and the ability to judge changing weather could determine survival.