One scene features boats docked on the sides of the Kandagawa being flushed out en-masse to larger, open bodies of water, to prevent them from getting caught up in the races and unnecessary hazard to the racers. It seems the Jet Racing Association's infrastructure is very extensive and impressive.
Just how powerful is the pressure on those water guns? They seem to be able to cause significant pain to someone hit with a direct shot, so it isn't far off to assume they can cause serious bruising or injury if you get hit someplace vulnerable like your eyes. It just makes the "purging" function of their wet-suits go from a blatant tool for fanservice into a serious safety hazard, not to mention plenty of questions as to how things can go wrong during a race. You can argue that experienced shooters know not to deliberately aim for eyes and other vulnerable spots, but then you have the question of beginners and large-spread weapons like bazookas and shotguns...
If the girls suffer Clothing Damage while racing, their clothes logically would fall in the river. Similarly, Emily casually tosses her bazooka in the river after using all the ammo and no one questions it. How exactly are they getting those things back and how much time and effort does it take?
