This book presents evidence that the surface of standing water cannot possibly be convex.
So there is no such thing as a drop of water? Because that's essentially what the Earth's oceans are (according to RET): a gigantic drop of salt water surrounding the rocky crust of the Earth, with the exception of the continents. If you look at it from a more distant perspective like that, you will notice that the oceans are not actually standing water at all. Not only are they basically a drop of water, they have currents as well and are therefore in constant movement. So they defy every possible definition of "standing water". In addition, presuming that the author's argument is just an observation of water in a still container or on a flat surface, the reason for the flat surface would be gravity. Due to the nature of gravity, there is no actual up or down in space, only "in" towards concentrations of matter (read:objects). The water on Earth is only strongly affected by the gravitational pul of Earth itself, which pulls it evenly inward to form a roughly spherical shape. The only other object that has a major effect on the oceans but not the rest of the Earth is the Moon, which causes the tides.
Well, then. I've contradicted a whole lot of FET doctrine just now, haven't I?