I’m old enough to remember when the term “Monoski” meant something like the above.
But these days it usually means a sitski mounted on a single ski, the alternative term is “Bi-ski” for a sitski mounted on 2 skis. At the Edelweiss program we tend to think of a monoski like a sports car, and the bi-ski like the family station wagon (I guess that’s a minivan these days). Everybody learns or drive in the family station wagon, those that pass their driving test (in our case the ability to ski the main green run top to bottom without tethers), might get given the keys to a sports car.
But I’ve heard that some other places do it differently. In particular I’ve heard that CADS Calgary see them as two separate disciplines, more like sit skiing vs 4 tracking. New skiers are evaluated on their level of disability (or ability) and judged whether they are likely to ever be able to drive a monoski untethered. If they could then they are assigned to the Monoski program immediately, and presumably trained quite differently from the bi-skiers.
I can see pros and cons. Our approach may be better for skiers who eventually achieve independence, but take many years to get there. It encourages bi-skiers to believe that graduation off tethers is an achievable goal. On the other hand, I would guess that the monoskiers progress faster in the Calgary system because the expectation of independent skiing without tethers is there from day one, for both the skier and the instructor.
As a footnote: I’ve heard the phrase “You should never tether a Monoski”, and I’ve heard people use term “Mountain Man” as a synonym for “Bi-ski”. Just to prove that we are nothing if not adaptive here’s a video of Jason, being tethered by me, in our Mountain Man Monoski. Jason skied in the Mountain Man Monoski with tethers in his first season. Since then he has graduated off tethers and is using a higher performance bucket.