@yego This is so great. Do you want advice? Don't touch it! 
Well, to be true, there's something is bothering me, but is a minor thing. The clouds on the background, two things. First, if you follow the line of the fin (the side that has a cut) it looks like the cloud on the bg continue the line and is bothering me because don't help to pull the subjects apart from the bg, but the contrary. Is bringing the cloud to the front and blending it with the subject. That is the thing I would touch for sure, to move a little the cloud.
The other thing is more like a matter of taste I think. Is the cloud behind the face of the swimmer. Is not like is wrong, but me, personally, would prefer if the face is against the blue or at least not so white. Take down the opacity a little could perfectly do for me. Now the hand has more central role than the face, and that's great if you intended, is nothing wrong. But I feel like an imbalance, like is too much, the hand is rock'n'roll star and the face is buried on the cloud.
But again, is great the way it is. I'm just saying what I would touch if the piece where mine.
Great light again, by the way. Do you always use backlight?)
Seriously don't touch any more, any new version is worst. Trust your gut not your brain.