It would seem that the authorities and some of the boats do try to look after their passengers.
In particular, the above article casts a spot light on two areas:
1. life jackets were on board
2. weather forecasts and predictions by authorities and boat crew are not very good. I assume it is a matter of balancing safety and passenger happiness and few tourists like to be transported all the way from Ha Noi only to find out their boat trip was cancelled.