The view of Professor Robert Schoch Schoch is a renowned figure, indeed notorious, for the case he's made, based on strict geological evidence, that … - Graham Hancock

To have followed the speculative vision of Behaim in his famous globe, or of others like him, would have been disastrous, even though their work represents the cream of fifteenth-century mapmaking and was known to Columbus. Indeed, as one commentator has observed, if his chart had been based on the Behaim scenario, 'Columbus could not even have known of the whereabouts of the New World, much less discover it.'
Yet not only does he seem to have known where he was going but, on some accounts, when he was going to get there:
'Now and then Pinzón and Columbus consult and deliberate — mutually discuss their route. The map or chart passes not infrequently from the one captain to the other; the observations and calculations as to their position are daily recorded, their conduct and course for the night duly agreed upon.
On the eve of their due arrival Columbus issues the order to stay the course of the armada, to shorten sail, because he knew that he was close to the New World and was afraid of going ashore during the obscurity of the night ...
How does he know the place and the hour?
'His Genius' says the Columbus legend in explanation. But the Map? The critics will ask, what did it contain? Whose was it? What did that map contain that was so frequently passed from Columbus to Pinzón during the voyage?'
I've presented my case that what the map may have contained was an accurate but ancient, and indeed antediluvian, representation of the coast and islands of Central America, notably the north-south-oriented Great Bahama Bank island, which Columbus — no less ignorant than any of his contemporaries about the existence of the Americas — took to be an accurate map of part of the coast of China and the islands of Japan.

It was Cesare Emiliani who first drew serious attention to the possibility of post-glacial superfloods. In a paper published in Science magazine in 1975, he and a group of colleagues presented startling evidence from deep-sea cores from the north-eastern part of the Gulf of Mexico. The evidence revealed 'a 2.4 per cent isotopic anomaly between 12,000 and 11,000 years ago', which the authors correctly interpreted as having been caused by 'the occurrence of major flooding of ice meltwater into the Gulf of Mexico ... centring at about 11,600 years before the present'.

The black mat formed on top of the layer of proxies,' Allen replies. 'Down here it has a lot of charcoal in it. But it also has algal remains so it's not just fire. The Younger Dryas changed the climate and made the area much wetter. Algae began to grow along the edges of the lakes.' He puts a hand on the black stripe along the arroyo wall: 'So the remains of about 1,000 years of dead algae, charcoal, and a lot of other stuff are all embedded in here, and at the bottom of it, where the impact happened, we find iridium, platinum, and a layer of melted spherules where the temperatures must have been so high that they would have melted a modern car into a pool of metal.