Tirediron is right, this is a great composition as regards the creek. I like how you've let it run off the left side of the frame a bit before coming back to exit the bottom of the frame.
I do find it a bit unfortunate that your friend is dead center in the frame. Besides being a generally less interesting place for a subject, in this case it means that while he is looking at the waterfall his back is turned to the meandering lower rapids, which I find as interesting as the waterfall. His pose on its own asks to be toward the lower left corner, so that he is looking into the frame. I'm not saying there is a better position for him in this frame, or a better position from which you could have shot this, just thinking of ways this could ideally have been better. This may just be an instance where the shot is stronger without the human element...did you take any w/o him in the shot?