downwind ROW boat obstruction rules

As is often the case, go to the definitions. In this case an obstruction is defined as "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"
My emphasis on the if. Its still an obstruction if you are not on a collision course with it. Does that make things simpler?

This is the point. The green boat is an obstruction for both boats. The definition doesn't say "without changing course when she is sailing directly towards it". It says "IF she WERE". If we're racing in Hayling Bay France and the Isle of Wight are obstructions. Its just that no action is needed to give room at them. So 19.2b applies. But outside doesn't have to do anything to give inside room to pass France or the IOW.



Edited by JimC - 05 Aug 22 at 6:27am

Originally posted by ClubRacer As I see it Green is an obstruction to Yellow and Blue after it has gybed.

Yes.

Originally posted by ClubRacer Yellow has 2 options, gybe in front or luff and sail behind Green. Yellow is entitled to choose which side as per 19.2A and Blue is entitled to pass in front of Green if Yellow chooses to do so 19.2B

Yes, although, I think if Y gybes, she's going to end up parallel and overlapped to windward of G, with B in the gas, possibly CASTN of Y. If B gets her nose into the gap and becomes overlapped on Y, to windward of her, then Y is now windward boat, required to keep clear of [G and] B, and required to give B room to pass between Y and G.

Originally posted by ClubRacer How would it work if only Blue was on the collision course and Yellow was not. Is Green still an obstruction to both?

As long as G is on stbd and B and Y are on port, G is the right of way baot an an obstruction to B and Y.

Whether a Y is required to give B room depends on whether rule 19 applies at all. Rule 19 applies between boats 'at' an obstruction. I think 'at' means 'when an inside boat needs an outside boat to give her room to pass between her and the obstruction'.

Whether boats are on a 'collision course' doesn't really matter, the issue is whether B needs Y to give her room to pass between Y and G. If B is on a 'collision course' with G and B needs space between Y and G to pass between them, then Y must give B that room.

Originally posted by ClubRacer If Yellow and Blue were on a collision course with Green, could Yellow hold its ground until Blue bails out behind Green and then gybe or would they risk a protest by infringing 19.2B?

Well, it sounds like you are describing the very thing that rule 19 is there to prevent: Y 'scraping' B off against the obstruction.

When Y and B are 'at' G, the obstruction, Y is required to give B, room, that is the space she needs, acting promply and in a seamanlike way, to pass between Y and B. so the test is going to be, how much space was there between Y and G when Y gybed away.

If Y's intention was as you describe, there probably won't be enough space, and Y will break rule 19.

And boats don't 'infringe' rules. They 'break' them.

Originally posted by ClubRacer I would presume Yellow could just argue they left Blue room had they have held their course a little longer

Well, that's going to depend on what the evidence proves about the actual amount of space, but Y is on very shaky ground.



Edited by Brass - 05 Aug 22 at 12:32am

Actually it depends if you believe in facts or unicorns .

Originally posted by ClubRacer I had changed infringed to break within a few minutes of posting the original, unsure how you managed to quote the pre-edit

'Cos I copied it from the email version that I got, to get rid of the horrible coloured text <g>.

Originally posted by ClubRacer Thanks for the answers they are exactly what I was after. New question: are any rules broken if yellow holds its course and green misses blue by a hair (less than a hull length) without having to change course?

That's what your animated diagram showed.

The answer is:

G did not change course or take any other avoiding action.

There was no contact.

See Case 50.

B and Y did not fail to keep clear.

No rule was broken.

But less than 1 BL, means, to me, nearly one boat length, which is a lot more than a whisker.

If, on the other hand, G had changed course and protested, then Y and/or B would have broken rule 10.

Originally posted by ClubRacer Same question again but blue and yellow are passing an anchored cruise liner which blue misses by a hair

Was it a seamanlike hair?

B is going to need to come into a protest hearing and prove that she was given less than some specific amount of space, which she needs to convince the protest committee was less than prudent seamanship required.