Wasn’t the consensus or “settled science” that the Earth was flat at the time?
You do realize that’s a myth I hope. In Columbus’ day it was common knowledge that the Earth was a sphere; in fact they also had a very accurate measurement for the Earth’s diameter (actually the polar diameter only, slightly less than the equatorial). Conventional wisdom at the time knew that the Far East was too far west to sail directly across the ocean (check a globe if you doubt it). Of course what neither conventional wisdom nor Colombus knew at the time was that a huge landmass was to be found a reasonable distance due west from Europe.