Methods to navigate open seas differ from culture to culture.
People accomplished amazing feats of navigation across open oceans well before modern Europeans took to uncharted seas. Vikings and Polynesians, for example, built sturdy boats and found their way without maps across vast distances by closely observing their environment.
In the harsh, stormy waters of the North Atlantic between A.D. 750 and 1000, waves of peoples from Scandinavia—collectively known as the Vikings—sailed west to settle Britain, Iceland, Greenland, and even North America. They hopped from island to island and also observed the presence of birds near land and their migration patterns.
Over thousands of years, Polynesians migrated across vast distances and spread their culture across the Pacific. But they left no written record. Modern voyagers have recreated their routes, canoes, and methods. They suggest early Polynesian navigators sailed from island to island by observing Sun and stars, wind and waves, and the behavior of birds and fish.
“If you want to learn to pray, go to sea.”