WRONG!!!!!! I doubt you have even seen pontoons or spatulas to make that comment.
to begin, reverse camber has nothing to do with the sidecut of the ski, it has to do with the verticle (when the ski is lying flat on the ground) curvature. a reverse camber sits like a boat with the tips up in the air, while normally skis have a space between their center and the ground.
And while ARGs are different than pontoons and spats, they are different because they added another curature to the sides, essentially having 5 sidecut statistics, while the pontoons and spats are designed after water skis and have a skinnier tip and tail than waist, but no extra curves. and yes the tip is wider than the tail, or else it wouldn't be very effective in floating. and as for the 160-130-120 dimentions of the toons, they actually get wider than 160 than taper back, making it 130 at the suggested mounting point.