Yes, yes, yes. Sorry couldn't resist and as we're getting up to the festive season I wonder if Singin' in the Rain will be shown again on TV?!
Anyways Noah built an Ark on the spec God gave him. It was 300x50x30 cubits in length, width and height. A cubit is as far as I can remember from the tip of a middle finger to the elbow, about 18 inches. So that is 450x75x45 feet in length, width and height. This is a huge undertaking if the Flood was a "local event". It took years to build and all the while Noah preached to the people living at that time. If it was a local event all they had to do was move out, yet this did not happen. Why not? Maybe because the fallen angels had to be put into a situation by which they could not use their force against all that Noah had done. These ones knew full well that if God decreed something, it would happen.
Yet they remained silent. They could of saved their wives or their children by sending them into the Ark. But their now demonised position made them think of only themselves. They came to earth to gratify their sexual desires and now they were willing to sacrifice their families knowing full well they could dematerialise their bodies and return to the heavenly realms and save themselves.
In addition the Bible states that it was God who closed the door to the ark. God's power is far more that that of angels. By this act alone, the fallen angels could not use their power to force their way onto the ark. If they could there would be little doubt as to their intention: kill Noah and his family.
So, if reasoned on, the Flood account had to be global, not local. God's anger against humanity is targeted against only those who refuse to listen and take action. The earth will never be flooded again yet we do face a great tribulation before Armageddon. Will that be a local or a global event?