There is very good evidence of a mesopotamian flood, which was the entire “known world” of the time, and almost certainly contained if not all of mankind, an overwhelming percentage of it.
The term “world” was used repeatedly in Genesis to mean this area (e.g., refering to Sargon (or variations of his name) as “king of the world” when we know there were other contemporaneous kingdoms in China).
A lot of cultures arose around rivers, so it’s not surprising that there are a lot of flood myths.
And the creation of the Black Sea probably played a part.
But proponents of the Biblical flood seem to be talking about a flood that covered the entire world as we know it today.
Hey cool. I was hoping somebody would jump on the discussion who held this viewpoint. I'd like to get some clarity as to why you believe as you do regarding the flood. Are you interested in a discussion along these lines?