The vertical cross is actually a skier doing acrobatics before splashing into the pool. They slopes are sprayed with water before just before the skier starts down. The pool is placid until a skier is coming down the slope, then the water is agitated with water jets or compressed air. I assume this makes for a softer landing, fewer injuries, maybe more like snow.
I'm gonna give the guy (or gal) below a 9.5, went a little crooked on the landing.
Below is the snowboard acrobatics area. Again, everything is sprayed with water before the launch. Jumpers land on this huge inflated balloon/mattress. The person in the air (middle left) is kinda hard to distinguish due to the background.