I know the boys are being drowned, but it seemed more like you were saying a bit more than that: that the player has to save a particular boy from a slow drowning.
I'm near the beginning of the game, so knowing that a) the boys are being drowned in a way from which they can be rescued, and that you actually can rescue one of them (instead of just being fucked around by the tricksy killer) saps some of the tension for me, which is a lot of what the game has to offer.
Ugh, maybe I'm just reading too much into it. Don't even tell me if I am or not. Maybe I just need to take a break from games media til I'm done...