Pardon my French, but that is ludicrous. There has been much flooding, but the planet has never been covered by a singular flood.
Okay, stop right there. Let me ask you something. How would anyone of that time period be able to tell you the entire planet was flooded? So far as they were concerned, the entire world was flooded, but they could only see the portion of it that they happened to be at. They just assumed the rest of it was underwater because their part of it was underwater.
There just isn't any scientific evidence to support such an extreme hypothesis.
No, of course there isn't, but there is no need to support that hypothesis. What they wrote can be adequately explained by their lack of knowledge, and one does not need to take literally the words of people who cannot know beyond their tiny speck of earth.
The myth of the flood came from early societies, like Sumeria and there are many flood myths throughout the Middle East...so no doubt there were vast and severe flooding events (The flooding of the Black Sea basin being a potential such event)...but never a world wide event.
The fact that there are flood stories from all over the world ought to be pretty good proof to a rational man that there was indeed floods in which the people believed their entire world had drowned. That they are so diverse geographically ought to be good proof that the phenomena was indeed quite widespread.
Have you read about the Scablands Megaflood?
https://www.nasa.gov/topics/earth/features/megaflood-legacy.htmlIt is this same phenomena that is believed to have cut England off from Europe. A massive flood water that destroyed the land connection between England and Europe.
Again, it doesn't have to actually be the entire world flooded at the same time, though with Tsunamis caused by massive Ice walls collapsing, it might have flooded every place within miles of the oceans.
These people were recounting real wars and societies and cities they encountered, but to take these stories as factual accounts is not credible...it does not mean the stories cannot still convey great meaning and moral teaching, but to take them literally is to set aside reason and common sense.
They were told from the perspective of people who could not understand these events except as something of a supernatural nature.
Let me tell you of another such occasion. In the 19th century, when people were making their way west to California, Washington, and Oregon, there was a valley that the tribal peoples warned the Pioneers to stay away from. The Indians told them it was full of evil spirits, and if they went into that valley, they would die.
Many settlers ignored it as superstition and went through that valley anyways. Astonishingly, they did take sickness and many died. There did appear to be "evil spirits" in that valley, and people eventually came to avoid it.
Today there sits a scientific research center on the edge of that valley. They study a specific tick that inhabits that valley and which is highly infectious with a very nasty virus that is generally fatal to humans.
The Indians knew nothing of viruses. All they could describe were "evil spirits" that would kill you if you entered their valley.
Scientific reality, told from the perspective of a person that could only see it as a supernatural thing.