Reconstructing Columbus’s first transatlantic track and landfall using climatological winds and currents

Abstract

An article in the November 1986 National Geographic magazine examined the question of Columbus's first landfall in the Americas. The author, Luis Marden, was the first to quantitatively include the effects of the winds and currents in reconstructing the transoceanic portion of the voyage. There seemed, however, to be two major weaknesses in his analysis. First, the leeway effect on the ship by the wind was ignored for that portion of the voyage west of 40W, the whole second half of the voyage. Second, currents from pilot charts were used with the corresponding speed determined by the prevailing current. We sought to reanalyze the track using the leeway effect for the whole transatlantic track and using more appropriate average vector velocities of the current. Using climatological winds and currents we found the island of San Salvador (Watling Island) to be the most likely site of the first landfall of Columbus. This paper discusses the effects of wind, current, leeway, and magnetic variation on the determination of the landfall.