Believer says: Noah’s Flood was a universal deluge.
But skeptic says: Well, the geological evidence doesn't point to a world flood like the one in the Bible. In fact civilizations went on as usual through the time of the alleged Flood.
Bible tradition says the year of the flood was sometime between 2200 BC and 2900 BC. But the thing is, a universal cataclysm didn't happen then. The Egyptian as well as the Chinese civilization went on as usual. Their writings and artifacts bear witness to the fact that they carried on with business.
Some theists claim there are deletions in Genesis 11:10-32--that is to say, deliberate ones--for the sake of brevity. The Genesis chapter contains the years of every generation from the Flood to Abraham. Theists insert artificial generations into the chapter to make the Flood older by several thousand years.
Recap: Genesis chapter 11 recounts the generations from the great Flood to Abraham, the father of the Hebrews. Abraham lived about 300 years after the Flood, thus about 1850 BC. Theists want the Flood date to be older, though, so they pad Genesis with artificial generations. Meanwhile, modern geology hasn't discovered any evidence for a global flood. Period.