Navigation Tools
The earliest forms of navigation relied on calculating the relationships between the navigator and the world around them. A navigator could find their position based on the position of the stars, sun, or moon (this is called celestial navigation); they could find which direction they were heading using a simple compass; they could use the landmarks around them to determine their position.
Compass
Uses a magnetized needle to find the earth’s magnetic north pole. Magnets, including the earth, have two poles. Since the opposite ends of magnets attract, the southern pole of a compass’s needle will be attracted to the earth’s north pole and will point north.
Sextant
Measures the angle between two points, such as the sun and the horizon while at sea or two landmarks when near land. When used along with a nautical chart, the angle between the two points can be used to find your position.
Pelorus
Resembles a compass, but has no magnet and does not point north. Instead, it is used to identify relative directions. The pelorus is used to view a landmark and find the ship’s relative bearing to that landmark. With two or more such bearings, a mariner is able to calculate the ship’s position on a nautical chart.