I dont really agree with counting the oceans but not counting the gaseous areas of the gas giants, but i guess it getd messy with how to portray it. Portray it as a liquid form of the gases so you have definite volume? Remove the liquids from the equation (but that would create MORE land on earth)? I dont know. It just seems like removing them from the equation creats an extremely small picture, but maybe that's the point.