FAR rules on "ground-effect" vehicles?

Let me make a clarification to my original post:

The machine that I'm considering is NOT GOING TO OPERATE FROM/OVER WATER. It
is not a flying-boat / hydroplane / Skycar / UFO thingie. It was designed as a
land-based aircraft and looks something like an untralight. It had wheeled
landing gear, wings, control surfaces, engine & prop, etc. However, it never
flew very well or very far... if it ever flew at all. There is no photographic
proof that it ever could or did leave the ground. Eyewitness reports lead me
to believe that it never flew out of ground effect, and never flew more than a
few hundred yards before being retired.

Now here's the rub: all of the flying Wright 1903 Flyer replacas that I know
of are considered (and are) true aircraft, thus requiring a PPL, N-numbers,
etc. They rely on sound aerodyamic principles and would be capable of flying
for miles at altitudes in excess of 10' AGL, given a very good pilot.

The machine that I'm researching does not benefit from any sort of aerodynamic
wing design. Its ribs are flat. If it flew, it was because large ammounts of
power were used to shove it into the air for a few hundred feet.

SO, is there a difference in the eyes of the FAA? And if so, what part of FAR
would govern such a machine? I realize this is a very unusual question, thanks
for your help.

Harry