Touching waves while flying has (apart from the often reported unreliable engine) no effect on the ah/mh-9.

Waves should shake the airframe, heavy waves should be able to flip the helicopter so that gaining altitude again becomes hard or impossible.
Hitting waves seems to have some kind of effect on the ka-60. It seem to turn around the rear tire though which means that a strong effect already happens when only the tire touches the waves.
Closed frames should also be able to swim for a while.

On a side note ah/mh-9 "drown" the same way in water as they fall while being in the air. They should sink like the ka-60.