The voyage of Christopher Columbus in 1492 is one of the most significant journeys ever made by man. It led directly to the colonization of America by Europeans, something that has had an enormous impact on the modern world. But who was Columbus? How did a relatively poor Genoese seaman persuade the monarchs of Spain, one of Europe's mightiest nations, to back a scheme based on a totally inaccurate assessment of the size of the world? How did Columbus, who was not a trained navigator, manage to make his way across the Atlantic Ocean and return safely to Spain? Where did he make his first landfall in the New World? To answer these questions it was necessary to have an all-round understanding of 15th-century navigation. The theory was understood, but no one had really tested the principles for hundreds of years. Without practical evidence it was impossible fully to judge the ability of Columbus as a navigator and seaman. The distinguished navigator, Robin Knox-Johnston, therefore decided to follow his course. An astrolabe replaced the sextant and even the compass on his boat "Suhaili" had its corrector magnets removed before the voyage started. This is an account of the voyage. It offers insights into the kind of ocean crossing that Columbus experienced. As the journey progressed, the sea began to yield some of its secrets, the Sargasso weed revealed some of its myriad of colours, birds were seen on uncharted flight paths and a curious alteration in the sea swell caused by islands out of sight over the horizon was noticed. Using an astrolabe and a primitive method of judging speed and ocean currents, the author gives an indication of where Columbus may have landed in the New World. The return to Europe was a near-disaster. Sailing into the Atlantic in November, "Suhaili" ran into an appalling storm, during which she was thrown over four times, losing her masts in the process. Although disabled, the boat continued its passage across 1600 miles of stormy ocean under a makeshift jury rig.