This vid is a blast from the past, 59 years ago to be exact. The oldest continually active ski club in the country still puts on 3 shows a week during the summer. This vid is from 1953 and shows early jumping and what appears to be early swivel skiing and doubles. Doubles was actually an event held with traditional waterski tournaments until the late 60s or early 70s.
The best part comes late in the vid with boats jumping the ramp and a boat on hydrofoils. Who needs a Sky Ski when you have a Sky Boat?