Управление каяком -- это вам не управление автомобилем

To put this metaphorically, we are not driving a car, with gas, brakes, reverse and a lot of choice as to route. We are steering a kayak, pushed rapidily and monotonically down a route determined by the enviroment. We have a (very small) degree of control over our course in this particular stretch of river, and that control does not extend to being able to reverse, stop, or even significantly alter the direction we're moving in.