Charts help captains of ships and pilots of airplanes navigate to their destination quickly and safely. They are like maps, but for the sea and air. There are two kinds of charts: nautical charts and aeronautical charts.

Nautical charts feature information about the sea, such as depth and behavior of the water in particular areas. Nautical charts detail where swells, tides, and ocean gyres develop. Nautical charts also represent features of the sea floor, such as canyons and reefs. They may contain the locations of man-made features such as buoys, lighthouses, and harbors. Sea captains use this information to plan their routes. They also use the charts to determine the location of their ship.

Aeronautical charts show features of the land such as mountain ranges, bodies of water, tall buildings, airports, and safe landing areas for pilots. They also show the distance between certain points and the official airspace of different countries. Aeronautical charts typically display different radio frequencies for the areas they depict, so pilots can call for assistance in an emergency or bad weather. These charts help pilots navigate their airplanes and determine a safe flying altitude.

Both types of charts include information about the Earths magnetic field. This is important because equipment can experience irregularities as vessels approach the magnetic north pole or the magnetic south pole.

Most charts are printed on large sheets of paper and come in different scales. Some charts depict a very small area, such as the coastline around a harbor. Others depict an entire ocean or continent. There are also electronic charts, created using a geographic information system (GIS). GIS charts are stored on computers.

chart
Submariners use a chart to navigate underwater.

Chart Error
Nautical charts that Christopher Columbus used when he set off from Spain showed nothing but ocean between him and eastern China. That's why his discovery of the Americas was such a lucky, lucky surprise.

aeronautical chart
Noun

map designed to help navigate aircraft.

airspace
Noun

region of the Earth's atmosphere controlled by a particular nation or country.

Noun

the distance above sea level.

buoy
Noun

floating object anchored to the bottom of a body of water. Buoys are often equipped with signals.

Noun

deep, narrow valley with steep sides.

Noun

type of map with information useful to ocean or air navigators.

Noun

one of the seven main land masses on Earth.

Noun

any system for capturing, storing, checking, and displaying data related to positions on the Earth's surface.

Noun

part of a body of water deep enough for ships to dock.

irregularity
Noun

an unusual behavior or occurrence.

lighthouse
Noun

structure displaying large, bright lights to warn and help ships navigate coastal waters.

magnetic field
Noun

area around and affected by a magnet or charged particle.

mountain range
Noun

series or chain of mountains that are close together.

nautical chart
Noun

representation of spatial information displaying data on bodies of water and coastal areas.

navigate
Verb

to plan and direct the course of a journey.

north magnetic pole
Noun

constantly moving area where compass needles point from all over the Earth.

Noun

large body of salt water that covers most of the Earth.

Noun

an area of ocean that slowly rotates in an enormous circle.

radio frequency
Noun

range of electromagnetic waves over which certain information, such as sound, can be communicated.

Noun

a ridge of rocks, coral, or sand rising from the ocean floor all the way to or near the ocean's surface.

route
Noun

path or way.

south magnetic pole
Noun

constantly moving area where south compass needles point from all over the Earth.

swell
Noun

stable, crestless wind wave formed far out at sea.

Noun

rise and fall of the ocean's waters, caused by the gravitational pull of the moon and sun.