Actually, scratch that, I think I forgot to change an order of magnitude somewhere, as in forgot to change from meters to kilometers or something like that.
Current mass of Earth is 5.9726*10^24 kg.
Radius of the Earth is 6374500 meters, giving us 9.8 m/s^2 gravitational acceleration at the surface. Factor in the height of Everest (8848M) and it's about 9.7 m/s^2.
So, water is about 994 kg/cubic meter, the average density of the earth is about 5500 kg/cubic meter.
I am, using the standard formula 4*3.14159*r^3/3 for volume of a sphere, coming up with a 9% difference in volume between sea level and the height of Everest, or about 9.94*10^19 cubic meters, way less than the current volume of of earth (but still more water than there is on earth today)
The problem is now...do we assume the water here today (about 1.38*10^12 cubic meters), was here, part of it was here, etc.? There had to be SOME water. Anyway, we do have to take our the volume of the dry land that is above sea level today. There are about 361 million km^2 of land times an average of 840 m elevation.
Plugging the mass of the earth, additional mass of the water MINUS the approximate volume dry land on Earth PLUS the additional 8848 meters into Wolfram Alpha, shows a gravitational acceleration at Everest with all of the water as... 9.94 m/s^2, slightly higher gravity.
I was still wrong, but at least I know know why. All of this, BTW, is rough math. Point out any errors I may have made...