I remember these silly water bike things that they had at FW during one trip. They were testing them out as rental items down at the marina. They let us use them free, just to get our opinion. They were HARD!! It basically looked like a bicycle on a pontoon. You would sit (after trying to balance) and pedal to make a rotor go around. It took many, many tries to even get balanced enough to pedal!
Yeah....they didn't last long.