Sorry if this subject has been done to death but I was rather hoping someone at the company might frequent these fora.
I was in a "head-on/crossing" situation with one of these ribs at the weekend.
I steered to starboard as we approached each other, he carried on his course (maybe with a hint of port helm?) so I made a more pronounced turn to starboard clearly showing him my port side, he carried on so I stopped and he passed in front of me from left to right about 4ft away.
This all happened at about 4 kts luckily, had one of us been going quickly I'm sure a collision would have occurred.
I really think that as a professional mariner, the skipper of the rib should have exercised more care and awareness.
I must say also, that I did not change course to put me in a stand on position but to let him know I had made a move to allow him more sea room, initially we were approaching head on.