Regardless that he is the stand on vessel and even if the ferry should have changed course earlier to go behind him - once this became a critical situation the ferry tried to avoid collision (backing and tooting) while the powerboat did nothing. In my mind that makes the collision 100% on him. He had the opportunity (and obligation) to avoid collision right up until the end.

Furthermore, when a powerboater lets himself run into a ferry, he needs to look in the mirror and ask what if that is a couple kids in a rowboat, a guy fishing, a girl kayaking. He has no business being on the water in a busy channel without watching where he is going. There is no excuse. He was a hazard to anyone on the water that day.

As an aside, and nothing to do with this particular event, but in Norway commercial vessels always have ROW over non-commercial vehicles. I think it's an inherent recognition that they are often more restricted.

It will be interesting to see what transpires legally.