How Early Explorer Maps Were Made

Long before GPS and satellites, explorers depended on hand-drawn maps to travel across oceans and discover new lands. These early maps were created by cartographers, who gathered information from sailors, journals, and older maps. Because they often relied on secondhand reports, early maps sometimes mixed accurate geography with guesses or legends.

Common Features of Old Maps

Many early sea maps, called charts, focused on coastlines. They showed harbors, islands, winds, and dangerous rocks. A key feature was the compass rose, a symbol that showed directions. Thin lines called rhumb lines stretched across the map, helping sailors follow a steady compass direction during long voyages.

Abraham Ortelius (1570)

Abraham Ortelius (1587)

Old maps were also decorated with artwork. Ships sailed across the page, banners labeled regions, and sometimes sea monsters warned of unknown waters. These artistic touches made the maps beautiful but also showed how little was known about the world.

How Maps Improved Over Time

As navigation tools improved, so did the maps. Explorers learned to measure their location using the stars, latitude, and longitude. Mapmakers developed new projections—ways to draw the round Earth on flat paper—making maps more accurate. The Mercator projection, for example, turned complex curved routes into straight lines, helping sailors plan long sea journeys.

Example Explorer Map: Waldseemüller World Map (1507) - See Above

This famous map is the first known map to label the Western Hemisphere as “America.” It was printed from many woodcut blocks and designed to form a giant wall map. Europe, Africa, and Asia appear in familiar medieval shapes, while the Americas stretch along the left side as long, narrow continents. Notes, labels, and decorative writing fill the oceans, showing how explorers were beginning to piece together a more realistic view of the world.

Discussion Questions

1. How did early maps help sailors even when they had mistakes?
2. Why do you think cartographers added sea monsters and ships to their maps?
3. How did latitude and longitude help improve the accuracy of maps?
4. What clues on the Waldseemüller map show it was made during the Age of Exploration?

Glossary

• Cartographer – A person who draws or makes maps.
• Compass rose – A map symbol showing directions.
• Rhumb line – A straight line showing a steady compass direction.
• Projection – A method for drawing Earth on a flat map.
• Latitude – Lines measuring distance north or south of the equator.
• Longitude – Lines measuring distance east or west of a starting point.