I don't like those charging hours. A number of people probably do their camera battery charging at the end of the day, after their dives, once they've got the camera case rinsed and the camera out to download pics from onto a computer. I suppose bringing an extra battery and charging it then swapping every day may become the norm.
Boarding the night before may let people avoid paying for a hotel, keeping costs down. If some customers didn't want to take advantage of the offer, more power to them, but now it's no longer a choice.
I hope at least some boats will devise a charging station that amounts to a steel trunk enclosing the chargers such that, when shut, even if a lithium battery-based fire broke out, it'd be contained.
Richard.