In civil offshore flying I have never heard of any pax being trained in hover exit or even heard of it being mentioned.
Doing it with 19 untrained pax and expecting anyone to survive with no rafts in a sea state that wouldn't "allow" ditching is wishfull thinking IMHO.
Power on "controled" ditching is the best of a nasty list of options in the event of a "Land or ditch immediately event" -again IMHO