P.S. I still don't understand the part about being one boat length away from the obstruction. Maybe somebody can explain that. [/quote]

I think it is a matter of relative size. For instance, if you are 10 mi away from a small island, a small change in course will allow you to miss it, but because when you are one boat length away, you can't miss it without substantially altering your course, the island is an obstruction. By the same logic, a lobster buoy will not be an obstruction, because when you are one boat length away, it will only take a small alteration in course to miss it. That is how I would read it.


From definitions section of RRS:

"Obstruction An object that a boat could not pass without changing course substantially, if she were sailing directly towards it and one of her hull lengths from it. An object that can be safely passed on only one side and an area so
designated by the sailing instructions are also obstructions. However, a boat racing is not an obstruction to other boats unless they are required to keep clear
of her, give her room or, if rule 21 applies, avoid her."

As the inside boat PW is entitled to room to pass the obstruction in terms of rule 18.2. [/quote]