Factual error: The Nina, Pinta, and Santa Maria are shown starting back for Spain at the end of the first voyage. In fact, the Santa Maria had wrecked by this time; the return voyage would be made only by the Nina and the Pinta.
Revealing mistake: At the beginning of the voyage, in the shot where the camera pans around the ships (just after the scene when the sail is being unfurled) we can see a jet airliner contrail mark on the sky.
Factual error: The film makes reference to three voyages, stating that the second voyage was the one in which Columbus fell out of favor; the epilogue says that Columbus took a third and final voyage to America. Actually, Columbus made four voyages. The second voyage tarnished Columbus's reputation, but it was the third voyage which proved to be his downfall.