Supra did away with river mode after 2018. I have it, tried to use it, but was kinda a pain, just adjust speed accordingly. To your point about boats being smart enough to know they are on a river, flow rates change almost daily, no way that would work. But yes, I have asked many many times to be able to select gps or paddlewheel. They program all logic to work with GPS. So if I unplug my puck, all I get is speed, it won't engage cruise control and therefore won't let you activate your surf system or enable auto launch for wakeboarding. It is frustrating at times, but you get used to it and most of the time it is only .2-.5 mph for wakeboarding or surfing.