A question about the flood myth, baraminology, and Pangaea

[FebruaryOfReason]

Where did all that water come from?
And where has it gone?

Hydroplate theory? Catastrophic plate tectonics? Lunar bukkake hypothesis (yes, really)?

And you probably thought Baraminology was the weirdest of the flood myth apologetics! :p

I was hoping someone was going to say "It rained".

I'm not electing myself one of Mancunian's more intelligent peers, but I'll see if I can explain it anyway.
According to my primitive queries; (apologies for the decimal system, creatards. I'll try to keep things down to 2 decimal places for you);

The Earth has a radius of 6,371 kilometres. This would give it an initial volume of 1.08321 x 10 ^ 12 cubic km
30000ft is 9.14 kilometres, requiring a new radius of 6380.14. This would give it a new volume of 1.08767 x 10 ^ 12 cubic km.

We have to work out how much land mass is currently sticking up above the water. That's problematic. Lets say that half of the volume in that 9.14 extra kilometres is already there in the form of protruding land mass - generous but not ludicrous.

This means 4669845677.45 cubic kilometres of water appeared from nowhere due to God Magic, then disappeared by the same mechanism, all conveniently leaving no evidence at all.

The more I hear about this God bloke, the more amazing I realise he is!