Tools Used by Early Explorers

Without the compass during the age of exploration it would no longer be called the Age of Exploration, because the amount of exploration and sea navigation would decrease exponentially. The compass made navigation easier by showing which direction is magnetic north and how it was relative to a map.

The astrolabe was the most important invention of the Age of Exploration, as seen through the facts that it could determine local time and latitude, measure the angles of stars, and locate the positions of the Sun, Moon, planets, and more components of astronomy.

• Stars and the Astrolabe. Phoenician explorer-navigators sailed from the Mediterranean along the coast of Europe and Africa, keeping land in their sights.
• Cross-staffs and Back-staffs.
• Lodestones and Compasses.
• Sandglasses and Chip-logs.
• The Quadrant Device.
• The Traverse Boards.

Oars

The earliest navigation methods involved observing landmarks or watching the direction of the sun and stars. Few ancient sailors ventured out into the open sea. Instead, they sailed within sight of land in order to navigate. When that was impossible, ancient sailors watched constellations to mark their position.

The theoretical accuracy of celestial position fix is within 0.1 mile of your true position. In comparison, a modern GPS should be able to give you an accuracy of less than 1 meter. While the theoretical maximum accuracy of a celestial fix is 0.1 miles, in reality you will probably never achieve closer than 1 mile.

The magnetic compass was an important advance in navigation because it allowed mariners to determine their direction even if clouds obscured their usual astronomical cues such as the North Star. It uses a magnetic needle that can turn freely so that it always points to the north pole of the Earth’s magnetic field.

The Earth rotates one full turn (360º of longitude) in one day. It therefore turns one degree of longitude in 1/360th of a day, or every four minutes. To calculate your longitude, you therefore simply need to work out the time difference between noon at your location and noon at the Prime Meridian.

Lines of latitude are called parallels and in total there are 180 degrees of latitude. The distance between each degree of latitude is about 69 miles (110 kilometers).

The distance between two successive lines of latitude remain constant (111km) because latitudes run parallel to each other and never meets the other latitude. But distance between the longitudes decreases as they go towards the Pole. Finally, all longitudes meet at the Poles.