Just asking.......is this for real or is it shopped in some way? I’ve watched this video multiple times and the skier’s speed does not appear consistent with what he is doing. He actually appears to slow down half way across then speed back up. Even if that is an illusion, you can’t skim that far without slowing significantly.
If it's real, then it could be an optical illusion making it look like he gains speed or at least doesn't lose speed.
When he first hits the water, the skier is traveling at an angle towards the camera and is probably going a lot faster than it looks. Up until the camera starts panning to the right, we can see the deceleration.
But once the camera starts to move, the skier's line of travel becomes more and more parallel to the screen, which makes his apparent speed closer and closer to the actual speed. So to the viewer, it looks like he's maintaining a constant speed or even speeding up a little, even though he's actually slowing down, just because the viewing angle is changing.
I bet that, if the camera was set up in a spot where it could catch the whole thing without moving, then it would look more natural.