The feat was both amazing and dangerous, especially given the limited technology of the time. The world was much larger than anyone had previously imagined, and relatively little had been recorded by seagoing cartographers. Much of what they compiled was inaccurate, but they were not completely in the dark.
They had the Martellus Map of 1489 [pictured above].
Cristoforo Colombo changed all that, and for that he should be remembered. He had big cojones, as did every sailor who joined him on his voyages into the unknown. I doubt that his financial supporters (including Queen Isabella of Spain) expected him to ever return from the first exploration, but he did, and he made several round-trip voyages after that, relying on seasonal trade winds.
Here’s to one of the greatest explorers in history.