A. the Flood was more than one and it was caused by the rapid melting of the ice caps as sea level rose some 400 feet everywhere.
B. The water in this second appearance of this non-story on FR is locked up in rocks and not a free flowing ocean.
C. Keep your knickers on and calm down.
And if the waters were to burst forth, what would replace its volume in the mantle?
I wouldn’t know. I wasn’t around