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The navigation technology mastered by the ancients is based on rich and perceptual experience. Sailors must learn to navigate by natural sky and scenery.
Before the rise of the modern shipbuilding industry, navigation relied heavily on the invaluable experience of sailors and some simple tools and techniques. European navigators only used compasses in the 12th century, but in the 5th century BC, the Phoenicians had driven crescent-shaped sailboats, crossed the Strait of Gibraltar, and exchanged tin for the British and Isles of Scilly. Before the 10th century AD, the ancient Polynesians in the Pacific had driven canoes across the ocean without a compass, and settled on small islands between Hawaii, Easter Island and New Zealand.
Early navigators usually sailed along the coast and docked at night. Just look at each visible landmark, or listen to the sound that can help pilot, such as the bell buoy or the sound of the fog whistle, you can figure out where the boat is already, and adjust the route accordingly. In addition, they already know how to use a sounding line to select a channel. One end of the sounding line is a lead weight, hollowed out at the bottom, and stained with a piece of animal oil or oil wax. In the 4th century BC, Greek historian Herod wrote: "When you are near the bottom of Africa, the water depth is only 20 meters, and if the oil wax on the hammer is contaminated at the same time, it brings up a certain kind of sediment. At the time, Alexandria is coming soon. This kind of learning is very important. In the midst of a foggy day or a storm, the captain knows where he is by the sounding line, otherwise the ship will crash on the rock on the shore or into the vast sea that will never come back. The ancient navigators were considered to be the first half of the astronomers. They had to study continuously in order to sail, and they gained rich experience and knowledge. During the day they roughly determine the course according to the direction of the sun. At night, they rely on the stars to navigate. Ancient Polynesians sometimes bring plenty of food and supplies, and take a long 18-meter canoe for more than 3,200 kilometers of voyages, which lasts for weeks. Without such experience and knowledge, such navigation is simply impossible. In the voyages that have gone through centuries of voyages, ancient navigators have discovered stars like Polaris that have determined their position and seem to never move in the sky. They believe that to grasp the fixed route to the east or west, you must make sure that you are always at the same distance from the horizon every night. Once they know the latitude of an island, it is relatively simple to sail there. The Greeks and Phoenicians knew that the Mediterranean winds and winds prevailed. They painted the wind direction into a compass-shaped wind map called the "wind rose." Estimate the wind direction according to the position of the sun during navigation, and then find the heading in comparison with the "wind rose". “Wind Rose†has been used by navigators and was painted on nautical charts in the Middle Ages. When navigators venture to sail away from the land or lose their way, they have other ways to save. Norwegian great explorer Froki Vijay Dalsen was the first to drive a Viking ship from Norway to Iceland. He always carried a cage of crows when he sailed. It is estimated that the crows will be released when they are close to the land. If the crow hovered over the ship and then returned to the deck, it means that the crow could not see the land, and it was far from the shore, and he continued to sail. However, if the crow is quite sure and flies away in a targeted way, he corrects the route and follows the crow, knowing that they will guide him to land. In addition, the sailors also rely on observation of cloud conditions and ocean currents to explore routes. Rising from the hot land of large chunks of land, like the convective clouds of the White Fortress, it is clear that there will be a circular coral island under the distant horizon. Experienced sailors feel the ocean and the slight currents on the deck to navigate. Some special odors on the land, such as the aroma of orange blossoms, the aroma of wild grasses, the aroma of wood burning, etc., can be blown by the wind to the sea 80 kilometers away. The sailor can determine the location of the land and the location of the ship based on the direction of the scent, so that it can return home as accurately as a radio navigator.
(Photo) As early as 2,000 years ago, stars, moons, clouds, and winds can guide sailors to sail at sea.