Why Maps Use Blue for Water

Look at a world map. You see green, yellow, brown, and red for land. But you always see blue for water. Why?

Long ago, map makers drew maps by hand. They used animal skin or paper. They used ink to draw countries and mountains. Water was hard to show.

Early map makers left water blank. They did not add color to oceans or rivers. Sometimes they drew small fish or ships in the blank space.

Then, map makers started to use color. They used red, yellow, and green for land. They needed a color for water.

They chose blue. Why? Because water looks blue. The sky reflects in the ocean. Water looks blue from high up, too.

In the sixteenth century, a famous map maker named Gerardus Mercator made new maps. He used many colors. His maps made blue the standard color for water.

Today, we use computers to make maps. But we still use blue. Blue helps us see oceans, seas, and lakes fast.

Blue is now a global rule. When you look at a map anywhere in the world, blue means water.

What is your favorite place on the map?