It's just like with sailing. There are all sorts of rules concerning who has the right of way in several situations. A lot of the time they aren't enforced. One reason is that a lot of the weekend 'captains' out there have no idea about what the rules actually are. That is different on the highway when you have a large sign designating no trucks in the left lane or specifying a truck and bus lane. They choose to ignore these directions because, despite the rules, the one rule that you have to be cognizant of and obey is that, inevitably the largest boat/vehicle will claim the right of way.

I always like the 18 wheeler towing a 50' trailer that goes blowing by you at 80 mph (in the lane to the right or left of you . . . it doesn't matter to them) has the back of the trailer plastered with signs that say: "don't pass on right", "vehicle Stops at railroad tracks", "this vehicle makes wide turns", "watch out for sudden stops", "if driver can't see you in his mirrors, he's likely to switch lanes and crush you and it will be your fault", and of course, the world famous "how am I driving. Report reckless driving to some phone number that has been mysteriously scratched out".