A waypoint is a reference point that helps us know where we are and where we're going. Whether we are walking, driving, sailing, or flying, waypoints help us find our way.

For centuries, waypoints were landmarks: rock formations, springs, mountains, and roads, for example. Physical landmarks are still used as waypoints today. Landmarks used as waypoints can be natural, such as a tree. They can also be artificial, such as a billboard.

Waypoints can also be physical things that hold navigation devices: buoys in the ocean or satellites in the sky, for example. These types of waypoints are used for collecting data. An ocean buoy can transmit information about water temperature, salinity, and chemical properties at that waypoint.

Coordinates

Coordinates are some of the most familiar and reliable of waypoints. Coordinates include degrees of longitude and latitude. Lines of longitude are imaginary lines running north-south on the globe. Lines of latitude are imaginary circles (called parallels) that run around the world from east to west.

Every spot on Earth can be located with the waypoints of longitude and latitude. Coordinates are used not only by navigators, but also by scientists and engineers. Wildlife biologists use coordinates to track the migration of animals, for example. Engineers use coordinates and other waypoints to plan the best place for a building or a park. Waypoints can also be used to document the movement of tides, currents, and erosion patterns.

GPS Waypoints

Satellites in the sky are part of the global positioning system (GPS). Satellites tell devices like smartphones and car navigators how travelers can get where they're going.

As people depend more on GPS to set them on the right paths, waypoints are becoming less tied to physical landmarks like mountains and rock formations. GPS waypoints are much more specific: They identify an exact spot on Earth.

Waypoints in the atmosphere or outer space usually include altitude. These waypoints let pilots know how tall a mountain is, for example.

GPS and other navigation systems will often combine waypoints. A specific set of coordinates is presented with a physical landmark to help orient the user.

GPS allows users to create waypoints, as well as use ones already in existence. Users identify and mark waypoints on base maps, and can identify more than one to create a route.

RNAV Waypoints

Area navigation (RNAV) is a method used by aviators to fly between a network of navigation beacons. RNAV uses fly-over waypoints and fly-by waypoints to indicate where pilots can safely make turns.

As its name implies, pilots must fly directly over a fly-over waypoint.

Fly-by waypoints, usually indicated by a four-pointed star, are much more common. Pilots can take a "short cut" and turn ahead of the fly-by waypoint.