TheWay
I have been reading this thread as flood geology is fascinating for me, and it seems that what hasn't been brought up is that the flood doctrine usually states that mountains were formed after the flood. Wouldn't this account for the seashells and wouldn't the water analogy be some form of logical fallacy as it doesn't really pertain to diluvial geology?
Indeed you have spotted a logical fallacy. It's commonly called the "Straw man" fallacy, and it consists of creating a new position which is different than the real position of one's opponent, and then attacking it.
You'll see plenty of it involving flood scenarios. A sure fire indicator is when they try to apply evolutionist "dating" techniques. The only time these could come into play would be in an OEC flood scenario, and those are hard to find.
Most of the recent flood models incorporate continental plates moving during or soon after the flood, and this is frequently omitted when straw men are being constructed.
Other distortions I've seen include requirements to form all land during the flood, assuming there were no seas before the flood, and a total lack of any floods after the big one.
You've got to keep on your toes.