"But first, what is a hydroplate? Before the global flood, considerable water was under earth’s crust. "
In order for Brown's "theory" to be valid, it stands to reasion that there must be evidence for both a global flood AND for this massive amount of subterranean water.
Strangley, I could see no such evidence even hinted at by Brown.
I was also underwhelmed by his section on liquefaction "explaining" fossil layers:
"Buried bodies with the density of a dead animal or plant floated to the top of the tank."
ON top of his tank's apparatus. Laying on top is not layering. THe does not even attempt to "explain" anything.
Brown is a snakeoil salesman.