I have ski's do this on my wake all the time. Now I slow down so they can't. I witnessed an almost fatal accident where one guy just missed landing on another. It is very cool to watch though. Makes me want a sea doo /supercharged!!
We use to jump skis like that in the Atlantic right off of Sebastian Inlet years ago when my wife worked for Bombardier. Takes a toll on your body. I've had friends blow out their knees on a bad landing.