[Smokin' Joe]

Freeze some of that water and stack it on the lumps. The water level goes down, and will rise when the ice melts.

Essentially, that is what happened with the far northern and southern latitude landmasses covered with ice sheets two miles or more thick.

While there was some compression of the continental crust into the mantle by the sheer weight of the ice on the continents, (google: Isostacy and Isostatic rebound), the overall effect was a drop in sea level because that part of the hydrologic cycle had battlenecked. When the ice sheets melted off, the continents rebounded somewhat, rising relative to their former position floating on the mantle (still occurring according to some), but the ocean basin water levels rose faster, inundating the coastal areas which had been habitable while the ice sheets existed.

[stockpirate]

When water freezes it expands, when the ice caps melt the water level goes down, not up.

Fill a glass with ice then water, cover with platic wrap and wait.....as the water melts the levels decreases.

[UCANSEE2]

Add to that a minimum of 5000 active volcanoes, and storms, overflowing rivers, etc., and you have an EVER MOVING geological surface. There are many factors which cause an apparent change of sea level.

The midwest US used to be the bottom of a sea. Did the sea level fall ? Or did the land rise?