Thursday, 30 April 2009

LTW Readers Q&A | 024

Uli sent this diagram, that happens often, but finds the solution unsatisfactory;
Summary of the facts:
5 boats of the Star-class all with port tack and overlapped are sailing downwind towards a leeward rounding mark to be left on port. When the first boat reaches the zone in position 2, the leeward Red boat has no possibility to give room to the four inside overlapped boats.
The Problem is:
In RRS 2009-2012 I found no rule that force Red to sail a course different from the course she was sailing and make it possible to give room early enough before the mark. (The words of the old rules “when they are about to round” are deleted)
Is a boat obligated to give room before the rule requires her to do so?
Well Uli, this is my opinion:
Because of the deletion of "when boats are about to round a mark" the border where rule 18 begins to apply is exactly defined. If one of the boats enters the zone - in your diagram the Blue boat - rule 18 is immediately in force. In this situation Red breaks rule 18.2(b) as soon as Blue enters the zone. She is not giving enough mark-room to all inside boats to sail to the mark.
The only way she can prevent that from happening is to ANTICIPATE!
And act accordingly before one of the boats reaches the zone.
You are correct in stating that there's no rule in the RRS forcing her to sail any other course, but the consequence of sailing it, is that she breaks rule 18.2(b) as soon as one of the boats enters the Zone. If she luffs before any of the boats (including herself) reaches the Zone and stays out, she indeed breaks no rule.
What about 18.2(e) you will ask? That rule states that if a boat is not able to give room she is not required to. Not quite. The exact wording has additional requirements:
(e) If a boat obtained an inside overlap from clear astern and,
from the time the overlap began, the outside boat has been
unable to give mark-room, she is not required to give it.
In this case the relevant requirement is "from the time the overlap began"! According to your diagram there was already an overlap well before the zone, so Red has no 'escape' in that rule.


  1. Jos said Red breaks rule 18.2(b) as soon as Blue enters the zone.

    I disagree

    Take the boats one at a time. At the instant Blue reaches the zone:

    1. Does Red fail to give Blue room to sail [a direct course] _to_ the mark? NO

    2. Does Red fail to give Green room to sail [a direct course] _to_ the mark? NO

    And so on

    At some later time, when an inside boat is _at_ the mark, Red will need to have gybed or run by the lee, to a position outside her direct course to the mark so as to leave room for the inside boat to sail her proper course _at_ the mark, from the instant that she becomes _at_ the mark (enters the roundabout/needs to start changing course)

    In practice, Red had better start giving room @2, but she does not break rule 18.2 at that point. One might think that Red will inevitably break rule 18.2 somewhere between @2 and the mark, but she has not broken it yet.

    In the layout shown, the inside boats are going to gybe onto starboard to sail their courses to the mark, so Red is going to be obliged to keep clear pretty soon in any case.

    But suppose we have this layout with the wind coming from the ENE (4 o'clock), so that Black can sail to the mark without gybing or sailing by the lee.

    @2.2 Black changes course to sail _to_ the mark. Yellow must respond by giving Black room to sail _to_ the mark (rule 18.2(b)).

    @2.3 Yellow changes course, firstly _to_ the mark, then further so as to give Black room to sail to the mark. Green must respond by giving Yellow (1) room to sail _to_ the mark (rule 18.2(b)), and (2) room to pass between Green and Black (a boat entitled to mark-room and hence an obstruction) (rule 19.2).

    @2.4 Green changes course, firstly _to_ the mark then further so as to give Yellow room between Green and Black. Blue must respond as Green did, giving room to sail _to_ the mark, and room to pass between Blue and the outside boat.

    @2.5 Blue changes course to respond to her obligations. Red must respond as each of the other boats did.

    Note that rule 19.2(c) will not apply to excuse any boat from giving room, because there is no continuing obstruction, and rule 18.2(e) will not apply because back up the course where the overlaps were established there was no inability to give room.

    Thus @2.5 Red should be on a course four or five boat-widths (including booms and whiskers) outside the mark.

    I think this is doable, if Red is on the ball, and that it is not inevitable that Red will break rule 18.2, but Red has no time to lose.

  2. Jos said She is not giving enough mark-room to all inside boats to sail to the mark.
    The only way she can prevent that from happening is to ANTICIPATE!

    I disagree

    She is not obliged to give enough room to _all_ inside boats. She is obliged to give enough room to _each_ inside boat. (but see my previous post in this thread)

    Jos seems to be relying on the Bryan Willis commentary about anticipation.

    I think the Bryan Willis point might apply between Black and Yellow: if @2 Black immediately changes course to sail _to_ the mark, and Yellow is between Black and the mark, then Yellow has not given Black the mark-room to which she is entitled, but when this happens, Red is three boat lengths away, and nowhere near Black's course to the mark. Red does not break rule 18.2(b) at this time.

  3. I hope the world agrees with Jos on this. Can anybody find a supporting Case or Call? Dick Rose seems to agree, on page 5 of his "New Section C" article:
    "This means that if, while outside the zone, an outside right-of-way boat forces an inside boat to a course that does not enable the inside boat to sail to the mark in a seamanlike way, the outside boat risks breaking rule 18.2(b) at the moment rule 18.2(b) begins to apply."

    For a clean argument in the example, I would apply the rule to the Red/Black pair, and say that Red breaks 18 when Red enters the zone.

  4. O'Hara,

    Agree with your technique: take boats pairwise.

    Can't agree with your conclusion: How can Red, three boat lengths away from Black, not be giving Black room to sail _to_ the mark?

    Black's course _to_ the mark will not converge with Red's course until they are pretty much _at_ the mark: THEN Red look out!

  5. Red is the easy one to deal with because she can get out of it by gybing. Yellow is more of a puzzle. Lets say the wind is a little on her quarter, so she cannot gybe without bearing away. She has to keep clear of green and before position 2, rule 18 does not apply. If black obtained her overlap from clear astern, could yellow give mark room from that moment? Yellow could slow and become clear astern of black. Perhaps that is what she needed to have done. And green and blue respectively.


  6. I don't agree with the statement tha tred cannot give the inside boats room. However, what will really happen, and red and the other boats had better anticipate this, is that Black will gybe to starboard, and after satisfying RRS 15 and 16, will become the inside ROW boat that is also entitled to mark room. Black should do this outside the zone and before Blue enters the zone in order to solidify that ROW status.

  7. I think it is a fundamental - though unwritten - principle that the racing rules do not require you to anticipate your obligations. But they do require you to act promptly once the obligation materializes. Although chaos is likely in the situation shown, it is not certain - though I pity the protest committee who will have to sort this one out.

    Fortunately the situation on the diagram is highly unlikely: Red will not want to round in fifth track from the mark and Black would have jibed to starboard and started shouting long ago...

  8. (e) If a boat obtained an inside overlap from clear astern and,
    from the time the overlap began, the outside boat has been
    unable to give mark-room, she is not required to give it.

    The "and" is not one or the other. Both conditions must be met before she is not required to give room.

  9. Dear Jos,
    And also Dear Uli;
    To Uli, very sorry for my long silence. I always wish you good health.

    Well, this is a good and difficult question. My sailing pupils have often asked the same question when I have been an instructor in the Racing Rules seminar this spring.
    My answers were quotations from two materials as follows;
    1. RRS 2009-12: New Section C Prepared by ISAF RRC Section C Working Party
    Other Mark-Room Rules: 18.2(d) & (e)
    • 18.2(e) imposes an anticipation requirement:

    2. Rules Master Website
    What's new in the 2009-2012 rules?
    18.2(e): ‘If a boat obtained an inside overlap from clear astern and, from the time the overlap began, the outside boat has been unable to give mark-room, she is not required to give it.’

    Suppose that you are Pink in the illustration. You have been overlapped with Blue for some time. Blue hails for mark-room when she reaches the zone.
    You might be thinking that you aren’t obliged to give mark-room because you are hemmed in by White and Blue? That is a difficult case to make, because rule 18.2(e) says that you are only relieved of your mark-room obligation if you have been unable to give mark-room from the time the overlap began, and that could easily be a long way before the zone.

    This time you are Blue. Let’s say that you established an overlap with Pink about two lengths before the zone, so there is no doubt that you are in fact overlapped at the zone. Can you claim mark-room?
    Pink does not have to anticipate the overlap. Her obligation begins only at the moment that the overlap begins. So you can claim an entitlement to mark-room only if you reasonably believe that Pink and White and Yellow can all move over in time. But if they try to give mark room but don’t have time or space, then they haven’t broken rule 18.

    The abovementioned situation is like Uli’s diagram. But the differences are 4 boats, which order is Blue, Pink, White and Yellow from inside to outside and the leading actor is the most inside Blue. Please refer the website.
    Sen Yamaoka JPN

  10. Brass, My hope was that the requirement to give room would be interpreted beyond the room occupied by one's own boat. Red's position at 2, by constraining the courses of boats in between, has the predictable effect of denying Black room to sail to the mark when Red enters the zone. Red had other choices available since the Red/Black overlap began that would potentially result in Black having her room. Thus, I hoped to argue, Red's action denied Black her mark room.

    I think the chain of rule 19 obligations will get messy in practice, with some boats ducking astern and different opinions on how close is keeping clear, and Red will come out better than in the scenario Brass describes.

    Anon, there is a principle that racing rules do not require you to anticipate others' actions, even if the actions could be expected. But there are cases where boats must anticipate the rules that will come into play as consequences of their own actions (rules 13 and 15 for example).

  11. Aha! Recent Q&A 2009-024 says one fails to give mark-room by pushing a middle boat into the path of the boat entitled to mark-room.

    In the Q&A it is the outside boat who is entitled to room, and an inside boat with late overlap pushes his way in. Scenario 1 question 3.

    Some Q&As have had strange logic, but I like this concept that "giving room" also means "don't push somebody else into that room". What do you all think?

  12. What will really happen in most races is that there will be a raft up, lots of shouting, no one will take a penalty and surprise surprise no one will protest either!
    Thats how the sailors deal with rules that they don't understand.

  13. It should be understood. The loss of "about ro round" has been traded for the certainty of the three boat length Zone. You now know when you are in breach. knowing when you are in breach lets you anticipate this and act accordingly.
    You need not anticipate another boats action to give it ROW, whan it say tacks. Here you will know you will have to give mark room you are not having to anticipate another boats actions.

    Mike B

  14. I am consense with OHara, Jos and Mike B. A boat (in the picture the leeward boat)has to anticipate a breach of a rule (in this case RRS 18.2(b)) early enough. But a boat need not anticipate another boats action if without of the other boats action she would not break a rule.
    Uli F

  15. Somewhat late, I notice that Rapid Response Team Racing Call 2009/001 addresses the same situation, with a different answer:
    Q. Yellow, Blue and Green are approaching a mark overlapped, with Yellow required to give markroom to Blue, and Blue required to give mark-room to Green. Does rule 18.2 require Yellow to give enough room to Blue to enable her to give mark-room to Green before Green is at the mark?

    A. Yes. ... Room to sail to a mark includes room to give room to, or keep clear of, other boats if required by the rules to do so.
    This logic is very similar to what Agnes used above. I hope this way of thinking eventually prevails.

  16. Oops; my last post above was meant for the thread "ISAF Q&A 2009-024". The call I cited applies to the situation here as well, but not to our discussion. Sorry folks.


Related Posts Plugin for WordPress, Blogger...