“When Being Wrong Was Right”
The debate in Columbus' day was not over whether the Earth was flat or round. Rather, the width of the ocean was the crucial factor; the distance between continents determined the cost and feasibility of an expedition. “The issue was the width of the ocean; and therein the opposition was right."1 Columbus had underestimated the circumference of the Earth and the width of the ocean by a significant number of miles.
The scientific community of Columbus' day believed that the Earth was a sphere of about 24,000 miles in circumference. Columbus calculated the earth’s circumference at about 18,000 miles. Others have demonstrated that Columbus made additional mistakes, for example, underestimating the length of a degree (45 versus 56 miles). His reliance on inaccurate information from Marco Polo’s Description of the World and Cardinal D. Ailly’s Imago Mundi and a statement in the Apocryphal Second Book of Esdras, which stated that the Earth consisted of six parts land and one part sea, instead of the real 3:1 ratio, led to numerous miscalculations. “To make matters worse, he made all his calculations in Italian miles, unaware that they were shorter than the Arabic miles used in many contemporary maps."2
It’s possible that if Columbus had been correctly informed on the Earth’s circumference and the length of a degree, he might have stayed home! Even considering his mistaken conclusions about measurements, “Columbus always rates the highest accolades from scholars when it comes to his seamanship. He was, without question, the finest sailor of his time." Virtually every student of Columbus accepts the opinion of Bartolome de Las Casas who wrote in his Historia de las Indias that “Christopher Columbus surpassed all of his contemporaries in the art of navigation."
 Samuel Eliot Morison, Admiral of the Ocean Sea: A Life of Christopher Columbus (Boston, MA: Little, Brown and Co., 1942), 80. “How Columbus Discovered the `New World,'” How in the World? A Fascinating Journey Through the World of Human Ingenuity (Pleasantville, NY: The Reader’s Digest Association, 1990), 357.  Robert H. Fuson, The Log of Christopher Columbus (Camden, MN: International Marine Publishing Co., 1987), 29. Quoted in Fuson, The Log of Christopher Columbus, 29.