Marine accidents tend to have shared responsibility.
Tend to? More like, almost always. Why? Because no one has "right of way" in this situation (and certainly not "right away").
There is a "give-way" vessel, and there is a "stand-on" vessel, but in the end BOTH have the responsibility to avoid a collision. If you "stand-on" all the way into a collision, when you could have done something to avoid it, then you are just as much at fault as the "give-way" vessel that didn't.
I think that too many people believe this is like driving a car, and that if they have "right of way" then any accident that happens is going to be considered the other guy's fault. Nope. Doesn't work that way. Not even close.