Whether by stars along a coastline or into the unknown of the open ocean, sea navigation tested the skill and courage of even the most intrepid explorers. In this episode of Johan Norberg’s New and Improved, Norberg tells their stirring story.

Ancient cultures navigated with sailing canoes or vessels with oars and rudders. A great leap forward came when Europeans mounted a permanent rudder to the sternpost. Equipping vessels with multiple masts and large sails, explorers became capable of crossing vast oceans.

From history’s early merchant vessels to today’s massive ships outfitted with stabilizers and GPS, sea navigation has made the world’s oceans a highway for global trade. More than 50,000 ships, licensed to 150 nations, carry every kind of cargo—24 hours a day, 365 days a year.