Except everything you suggest would require evidence.
Ocean currents cannot simultaneously cover the entire surface of the earth 8km high. Not even close.
Like I said, tidal wave..... it does not actually have to cover the entire earth all at once to have the desired effect. There is more than enough water on hand to do that.
Evidence of such comet impact? The asteroid that ended the dinosaurs left a clear cut impression, called the Chicxulub crater. The worlds oldest asteroid impact is still visible today - Vredefort Dome near Paarl.
On one hand it could currently be under the deep oceans..... a good place for a dent no?
It would have broken up upon entry or could have been a group to begin with, the earth is full of crater lakes.... why could almost all of them not have been formed at the same time.
Where was all the subterranean water stored? Where did it go?
Stupid questions, really.
Where is the geological record that supports the global flood?
The fact that the crust has many differing layers as if a lot of earth had been mixed up and then left to settle while covered with water?
How about the biological implausibility regarding having two animals of each kind in one ship? How was food stored, how were all the animals fed by so few people? What about insects and small mammals from South America, how did they get to the Middle East?
Again, the text says "kinds" not "species".... VAST difference in meaning. There is no proof that the original "kinds" even exist today in pure form.
Insects are waterproof and would easily exist on driftwood.
Why the assumption that all the animals entered the ark in mature form?
There are landbridges connecting all continents and most island chains, water at one point was lower than it is now just as at one point it was higher.
Quite interesting that you happily doubt recent historical text regarding events surrounding WW2, but you happily accept, without prejudice, a highly improbable, scientifically implausible fairy tale about a global flood.
The people that had a interest in twisting the facts of that conflict still have descendants twisting it today because it creates convenient sticks to beat opponents with..... however the core reasons and results for the war are not as easily twisted as the minor details.