RE: RC Shark
Math Vos's 6-footer shark operates a similar way, and I often thought of it myself, but didn't want to over-complicate things too much. Mind you, I suppose with a computer-mixer on the transmitter, this might be capable?
I actually found an article about a guy who built a dolphin with a working TAIL!! Pretty good, and I suppose the basic idea would be to turn his whole propulsion unit on its side??