If I'm not mistaken, and it's been YEARS since I used the tethered skis - you had an adult behind the child in the water holding them up. I think these trainers are principally designed for REALLY young kids. Those that you'd have some difficulty getting to sit still long enough to explain - flip the board up
You know what it reminds me of - is the kids we see on the ski slopes this time of year with the driving harness on
The parents are behind them sort of keeping them in check. I swear they can't be more than 4 years old.
With a wider, soft board at really slow speeds and their feet not attached, I thought this was a cool idea. Teach the little 4 year olds the basic's of standing up on the board. I can remember when James, at that tender age, was intimidated by the wake - this setup looks like you can drag the kid around at such a slow speed you literally don't create a wake.
Sheesh, look at James now!