We had a blast doing this (family of four - two adults, two teenagers).
We're from the middle of the UK and have had NO experience of doing anything like this before. We found it exhillerating and challenging, great fun. Most appear to be locals who can prperly water-ski - doing their jumps and flips. Great to watch. But yeah - us complete novices had a real blast too, so obviously there's something here for every skill level.
As mentioned this is an artificial lake and you sit on a knee board (or stand on a board if you have the skill) and get pulled around by the cable. Expect to get pulled into the water at times - all part of the fun.
Staff were friendly and helpful.