is a stretch, prima facie. But if you have a 'piston and cylinder' arrangement, where the 'cylinder' is filled with water, and the 'piston' made of solid rock, "floats" on the water, then this becomes mechanically possible to my brain. I can picture and appreciate that rock can under those conditions float on water, even though rock is 2-3 times as dense as water. With a piston and cylinder, the piston pushes against the fluid in the cylinder, and liquid water while not perfectly in-compressible (if I remember my Science studies correctly) is not perfectly compressible either (like a gas), so it would hold whatever weight the rock piston would impose upon it. The water wouldn't be crushed, iow.
So if that's the arrangement you have between water underground, and the ground, then we would expect the "Blue Marble" image from 7000 years ago would be more green and less blue.
Was this rock floating on water uniformly covering the earth? Or were mountain ranges like the Andes already extant? It seems from both the scriptures and from a model where there is rock floating on water, that it can't be that the mountain ranges were already there before the Flood. They must have formed during the Flood period.