Adamp, it does depend on the definition of "world" to describe the flood. No doubt the writers were referring to their wolrd as they knew it, not the world we know.
There is, apparently, some evidence that it might refer to an event involving the Black Sea. The Black Sea was originally a lake unconnected to the marine sea. The people involved lived on its shore, well below sea level. There is underwater evidence for occupation on the ancient shore there. Then one day the Bosphorus opened to the sea and the water poured in causing massive flooding.
I do not know if it is proven, and it may not fit all the events outlined in the Bible account.
