We are accustomed to using GPS to give us our location, but did you ever wonder how sailors were able to navigate around the world before the days of GPS?
With ocean currents, changing winds, dense fog, angry storms, relentless waves, and no landmarks in sight on the open seas, how could a ship set off from Boston and have any chance of reaching Bombay thousands of miles away? Yet in the 1600-1800s, global shipping was a big business, with ships routinely sailing from Europe and the Americas to ports in the Far East and back again.
While there are no visible landmarks in the ocean, there are marks in the sky—the sun and stars. Navigators used tools like the sextant in determining their ship’s longitude and latitude. The sextant allowed a navigator to measure the angle between the sun or star and the horizon.