It is possible to ski behind an amphib, however it is illegal - sez FAA or somebody.
3 ropes are suggested, it gets WEIRD when the wake disappears entirely, but the prop wash remains INTENSE.
It takes a LONG pull to get up even on 2 skis, so try to remember how you learned to get up on two and drop one. If you are too used to double high wraps fergettit.
The pilot has to know that it extends the take off distance considerably, dragging a skier through the water is a LOT of extra drag, even dragging a skier ON the water takes a lot of power and extends take -off distance.
DO have a chase boat, at some point the plane has to climb and the skier has to let go - obviously the plane can't come back for a dropped skier.
Don't ask how I know this.