People created maps of the seas and oceans to help them with trade, exploration, and travel. In ancient times, people used the position of the stars and the Sun or a compass to chart the seas. Through the centuries, maps of the seas have become more accurate and precise as new tools and technologies have been developed for mapmaking. Today, mapmakers use an array of technology, such as radar, global positioning systems, and satellites, to make maps. This book explores the different types of sea charts and how these documents have changed over the years.