Before revision: In this context, the Portuguese discovered the two large volta do mar (meaning literally turn of the sea but also return from the sea) currents and trade winds of North and of South Atlantic ocean (approximately in the first half and in the late 15th century respectively), that paved the way to reach the New World and return to Europe, as well as to circumnavigate Africa in western open sea, in future voyages of discovery, avoiding contrary winds and currents.
After revision: In this context, the Portuguese discovered the two large volta do mar (meaning literally turn of the sea but also return from the sea) currents and trade winds of North and of South Atlantic Ocean (approximately in the first half and in the late 15th century respectively), that paved the way to reach the New World and return to Europe, as well as to circumnavigate Africa in western open sea, in future voyages of discovery, avoiding contrary winds and currents.