Wow I cant believe that this is still talked about.
SO SO SO MANY REASONS ITS BULLSHIT!
Few not ever mentioned.
1. Water Salination. If the flood water came from rain or undergrounds springs - they would have been FRESH water. So that water would have mixed with the Saltwater in the oceans at the time. Imagin how salty the ocean water would have been pre-flood then? Sea life as we know it would not have been able to live in that water. Think - Dead Sea. Not many fishies swimming there, plus the all would float.
2. Bugs. Ah - did Noah save all the insects? Where were the bees, or the millions of other insects that are needed to have a viable ecosystem?
3. Slate cleaner. If there was a flood as described, and you had continents rising and falling (which is so stupid), the entire surface of the earth would be scoured clean. No plant life would survive. Then have it under salt water for an extended time to make sure its all dead. How did the plant life all come back when noah got out of his boat? Where were all the bugs (bees) that would be needed to pollinate plant life? There are about a million other moving parts what would have been needed that would have been erased by a 'flood'.
There are so so many more.