Obviously, the only thing that is able to flood is a basin on a relatively flat surface.  It is impossible for water to encircle the outside of a globe.  

Discussing Noah's Flood with a friend the other day and I remarked that when churchmen were conned into accepting heliocentrism in 1820, the heliocentrism they adopted was already an evolved one, thanks to Charles Lyell's Nebular theory of 1796. From then on nothing in Genesis was safe. Needless to say the same went for the Flood. Go check your Catholic encyclopedias and you will find it has been demoted to a local flood.

‘Deluge. The great flood which covered the whole land or region in which Noe lived (Gen. 6:1-9:19). God sent this flood to destroy all men in this region because of their wickedness. Noe and his family alone were spared (Gen. 6:1-8).  Scriptural scholars say that the flood did not necessarily cover the whole Earth as we know it today; some even hold that it not necessarily destroys all the people on the Earth.’ ----- The Holy Bible: The Catholic Press Inc. Chicago, 1951.

So what are the consequences of this we asked each other. Well, God must have lied when He said he would no longer punish man with such a flood like Noah's. Look around the world today and you will see local flood after local flood. Do most Catholics believe in anything these days?