the mindset was as the stand on vessel (the one with the right of way) meant that if you were hit it was the other guy's fault.

Now the thinking is (and I agree) all parties have to do what they can to prevent an accident. So, it you have the right of way you WILL be found partially liable to some extent just because there was a collision. You can't just watch it happen because you were in control of the stand on vessel.