When they voyaged back to Scandinavia, the Vikings could catch the Gulf Stream, which is part of the North Atlantic Gyre. Sailing on the Gulf Stream is like taking a fast-moving river through a sluggish ocean. It travels north along the east coast of the Americas and then veers out into the Atlantic around Newfoundland. Reaching the British Isles, it continues north into Europe. It moves at more than 100 miles (160 km) in a day, and its width—visible because it is a different color from the surrounding water—is some 40 miles (70 km) across.
