Consider, the boat engine has to also move the boat and itself. It takes much more force to accelerate the boat, get it up on plane, haul the mass of the boat, the engine, the fuel, and the passengers.

The wake board is much easier to plane and that is not a little drone. I have pulled skiers with my Hobie 16. A wake board would be MUCH easier.

If you have skied much at all, unless you are doing deep hard cuts, you know the pull on your hands is not very much after the initial jerk to get up on plane. I would guess between 25-30 pounds at most. Well within the capability of a large drone.