Wednesday 29 February 2012

Seven at the Leeward Mark; Part 3

Instead of keep repeating my arguments in the comments, I have another situation to explain why I think that the three outside boats don’t have rule 18 rights or obligations between them in this post: Seven at the Leeward Mark, LTW Readers Q&A (60)

Again I’ve created a much simpler situation involving three boats:
But this time they are all overlapped. The leeward mark has to be left to port.


In position 2 Red reaches the zone. From that moment Red has to give Purple AND Grey markroom.
Purple however has not reached the zone. And does not have to give markroom to Grey as long as she does not enter the zone. Because for her series score it is beneficial that Grey does not finish in the first half of the fleet, Purple decides to luff and force Grey up. She complies with 16.1 and gives enough room to Grey to keep clear.

In my opinion she is allowed to do this.

If not, this chain would never end. Add a fourth or a fifth boat and they would not be allowed to luff as soon as one boat is in the zone, if - as the argument in our seven boat scenario is commented upon - rule 18 was switched on, between all boats.

Rule 18 is on between Red and the other two, but not (yet) between Purple and Grey.

J.



23 comments:

  1. Nothing new... 18 applies to sets of boats.
    Red has to give mark-room to both purple and grey (not just pairwise).
    Back in your first example, dark blue, the most outside boat, has to give mark-room to all the inside boats that are in the zone. As CASE 114 clearly states, dark blue also has to give space to the sandwiched boats to give mark-room to all the inside boats that are in the zone. End of story :)

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  2. It is possible for more than one rule to apply at a time or for different situations to be allowable under the rules.
    Rule 18 does apply at position 2 between all three boats as, if purple were to sail straight on red would be required to give room to purple and grey. The fact that purple is not at that stage obliged to give room to grey is not relevant. At position 3 red is still obliged to give room but does not have to take any action as the other two boats have luffed away.
    Your 7 boat scenario is different as the outsdie boat cannot luff or she would break 16.
    When all boats are overlapped I believe 18 does apply as without it the rules do not work. I do not think this type of discussion where higly technical interetations which defy the logical and sensible operation of the rules is particularly helpful to the sailing world.

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  3. what is illogical about the whole scenario is you have seven skippers of seven boats heading into a big mess and they are all on port tack. I have been inside boat in this situation and prior to the zone the outside boat tried to head us all up. All of them were on port tack, but I had jibed to starboard. There was a lot of yelling, by the outside guy, but the boats closer were yelling back, we can't head up Davis is on starboard.

    If the outside boat can't head up the boats in between because I am on starboard. Why is it that the outside boat can head them up when I am right of way boat because I had overlap at the zone?

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  4. Jos says;
    >In position 2 Red reaches the zone. From that moment Red has to give Purple AND Grey markroom.
    >Purple however has not reached the zone. And does not have to give markroom to Grey as long as she does not enter the zone.
    -----
    My opinion, it is simple and clear.
    1. Rule 18.1 states "Rule 18 applies between boats which they are required to leave a mark on the same side and at least one of them is in the zone.".
    In this case, in position 2 boats are Red and Purple and Grey, and Red is at least one of them.
    Therefore Rule 18.1 applies to Red, Purple and Grey.
    Then it is natural that Red has to give Purple AND Grey mark-room.
    And also Purple has to give markroom Grey whether Purple and Grey enter the zone or not.

    2. Rule 18.2(a) states "When boats are overlapped the outside boat shall give the inside boat mark-room...".
    Then the outside Red boat has to give the inside Purple boat mark-room, and also the outside Purple boat has to give the inside Grey boat mark-room.
    Sen Yamaoka

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  5. Does not help relative to the old scenario.
    18.2.a applies when 18.2.b does not.
    Mike B

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  6. Since opinions don't seem to come together, I'll consider doing a Q&A.

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  7. WHy not wait until we get the revised rule 18and see if that helps.

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  8. In the above three boat scenario, Jos’s interpretation feels right, but I cannot find any flaw in Sen Yamaoka’s literal interpretation of the rules.

    I think a Q&A is warranted. Perhaps something like:

    Q&A Proposal
    Question One:
    In the first sentence of rule 18.1, does the phrase "applies between boats" refer solely to each possible pair of boats, or can it mean “amongst any number of boats”?

    Question Two:
    In the above three boat scenario, can Purple luff Grey after position 2?

    Question Three:
    In the seven boat scenario, does rule 18 apply amongst the three boats that are not in the zone?

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  9. We are actually getting somewhere, I feel. Now I understand better what Jos and Uli mean about applying pairwise, and in this light disagree with Sen Yamaoka's interpretation. If that interpretation was correct, as Jos pointed out earlier, then the whole fleet would be bound by 18 to every other boat as soon as the leader entered the zone.

    At the same time, I disagree with the extreme (and incorrect in my view) implication of the statement that the rules "only apply to pairs of boats," which is not in the rules. I would say the rules apply to the relevant subsets of boats.

    I quickly looked for 64.1c cases in the casebook, to find an analogy to the seven at the leeward mark scenario. Case 11 has a PL boat breaking rule 19 against PW. Include a PW2, to windward of PW. Assume that PL leaves enough space for PW to pass between her and the obstruction, but not space for PW2 to pass between PW and the obstruction. According to the Uli-Jos logic, PL is only bound by 19 to one other boat, PW, and PW is stuck between breaking 19 towards PW2 and 11 towards PL. Wrong. PL is also overlapped with PW2 and 19 also applies between them. PL must leave enough space for PW to pass between her and the obstruction, enough space for PW2 to pass between her and the obstruction, but /and this is crucial/ must also give PW enough space to fulfill her obligations towards PW2 under rule 19, namely enough space for PW to leave enough space between her and the obstruction.

    Analogously, dark blue must give mark-room to light blue (18.2, "pairwise"). Both my example above and case 114 imply she must also give space to red to fulfill her obligations towards light-blue under 18.2, even if red does not have right to mark-room from dark blue. Now, if red can (in a seamanlike way) fulfill her obligations towards light blue and at the same time keep clear of dark blue under 11, then red must do so. But red is NOT in an impossible situation just because light blue is not an obstruction to her. It may have been a good thing to include mark-room in the definition of obstruction, but this is not an example of a "problem" from deleting that from the definition, in my opinion.

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    1. Hi Latindane-
      In the case 11 scenario, S is an obstruction, so I don’t see how that is analogous.

      You seem to have changed your argument a bit. You say that in the 7 boat scenario Dark Blue…
      > must also give space to red to fulfill her obligations towards light-blue under 18.2, even if red does not have right to mark-room from dark blue.<

      That is true between positions 2 and 3, as 16.1 requires Dark Blue to give room to Purple and Red to give mark-room to Light Blue. Is that also true at position 2? I don’t get that from the cases cited. Only if your earlier argument is correct, that 18.2(a) applies amongst the 3 boats not in the zone.

      At position 2, if 18.2(a) does not apply amongst the 3 outside boats, with 16.1 off, and Light Blue is not an obstruction, I still feel that Red is stuck in an impossible situation, between breaking 18.2(b) or 11.

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    2. Hey Goomer,

      Case 11: the point is that PW2 is NOT an obstruction to PW, just like light blue is NOT an obstruction to red.

      I don't recall saying that 18.2(a) applied to all boats... I think I said rule 18 applied to all boats. I don't think that 18.2(a) applies between the three boats outside the zone (which is why I posted a "clarification" post, seeing where it was going). Different rules within 18 apply to different boats depending on whether they are overlapped, inside the zone, clear ahead, etc. In a sense I agree with Uli-Jos in the sense that one can look at which rules apply "pairwise" as long as one does not forget, in doing so, that there are other boats in the water which affect the possible maneuvers that a boat can actually make.

      Let me open the other post, with dark blue and light blue for the positions bit. OK, in position 2, light blue is inside the zone, and overlapped with dark blue. 18.2(a) (and apparently, more appropriately 18.2(b)) says that dark blue must give light blue mark-room. An almost direct application of case 114 says that Dark blue must "give enough space to [purple and red] to enable [purple and red] to give mark-room to [light blue]."

      Does this clarify my position?

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    3. Maybe I can make my position clearer with a statement which I think we all agree on and a question.
      - Dark blue must give mark-room to light blue.
      - How can dark blue give mark-room to light blue without giving space to purple and red to give mark-room to light blue?

      Delete
  10. IF 18 applies amongst any number of boats - when the leader enters the zone of a leeward mark, rule 18 “applies” to all boats on that leg. Practically speaking, they are not “bound” by 18 unless they are overlapped with her, or close enough to need to take action to give her mark-room.

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    Replies
    1. Well yes... if the leader enters the zone overlapped inside, or clear ahead, of all the fleet, the whole fleet is bound to give her mark-room by 18.2(b). This is often used by team racers use to their advantage.

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  11. Doesn't the Preamble of section A provide us with some guidance?

    It states something like "*A boat* has right-of-way if *another boat* has to keep clear", to me this seems to refer singularly to a single boat and one other single boat, i.e the rules apply pairwise. We then read rules 10 through 17 and it seems to me that the rules refer to an individual pair of boats albeit implicitly.

    By extension when we get to rule 18 why don't we continue this supposition?

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    Replies
    1. Hmmm... too many conversations at the same time. Pairwise application is fine, as long as you don't ignore other boats in the picture. In this particular case, for example, if one independently views the "pairwise" rule relation between dark blue and purple, and ignores the fact that both purple and dark blue have to give mark-room to light blue (you can view each of those relations "pairwise" if you feel), one ends up at an impossible situation for purple. Which is the whole problem, and a very good reason for rule 64.1(c) to be a rule.

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  12. The comment tree makes it kind of hard to follow up... maybe I can move my question to a new comment thread.

    I think after reading the different interpretations that have made me think more about the rules, I can boil down my interpretation of the rules and case 114 to something we all agree on, followed by a question:

    - Dark blue must give mark-room to light blue.
    - How can dark blue give mark-room to light blue without giving space to purple and red to give mark-room to light blue?

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    Replies
    1. Your questions are valid and of course we all want this to be the outcome.
      The problem however is that - at this moment - the rules give no solution to 'demand' this of Dark Blue.
      She must give mark-room to the 'inside the zone' boats but has no rule 18 obligation toward the 'outside the zone' boats. They must keep clear of Dark Blue.
      That is the whole issue. Sometimes the rules don't cover a situation and we change them.... or not. There are other situations where the rules don't have an answer.

      Delete
  13. You managed to not answer the question within the rules :)

    What about the obstruction question: some rock is coming up, three boats are on port tack: PL to leeward, PW immediately to windward, and PW2 to windward of PW, all overlapped.
    PL is overlapped to both. Say 1.5 boatwidths is enough space for a boat to pass between the obstruction and another boat. PL has to, pairwise, leave enough space for PW to pass between her and the obstruction, and leave enough space for PW2 to pass between her and the obstruction. With your interpretation of the rules, PW has only right to space between PL and the obstruction from PL, and sure enough, according to that interpretation, the rules give no solution to "demand" enough space for PW to give space also to PW2. I disagree. Case 114 can be applied to both cases, and in both cases windward is not an obstruction to the "sandwiched" boat.

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    Replies
    1. With an overlap the rule is much simpler and there is no zone.
      If you have an overlap and you can give room, you must give room. Since PL is overlapped with both PW and PW2, she has to give room to both.
      I never intended to say that ALL rules apply only in pairs. I only say that rule 18 only applies between two boats, when one of them is in the zone.

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    2. I can see there is a difference in the example; PL does have some obligation to PW and nit only to PW2.

      I guess this is as far as I can get. If only the answer to question 1 in case 114 did not say that B is entitled to mark-room, we would agree here. Or if the answer was simply "Yes," without any further explanation, I think we would also agree.

      A Q&A could be rather simple... does the answer to question 1 in case 114 change if B is not in the zone?

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  14. Hi Jos,

    i know this is already a bit older, but I recently have been asked a very similiar question which is related to the scenario above. As it looks to me, there hasn't been changed much on the relevant rules...
    So my question is whether there is an answer to the question, that in Position 2 of your drawing, Grey is entitled to mark-room from purple, without these 2 boats being in the Zone.
    In Other words: Can 18.2 b) apply to 2 (ore more) boats when neither of them is in the the Zone? (i.e. the rule is switched on by a third boat)

    My answer was no, now I'm not sure any more.
    Have you submitted the Q&A?

    Cheers

    Heiko

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    Replies
    1. I have not submitted a Q&A. I don't think the latest rulebook has changed anything in this scenario. Because Purple is not yet in the zone, she has no obligation to give mark-room to Grey.

      Delete

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