| Szabályok | ||
|---|---|---|
| Racing Rules of Sailing for 2013-2016; Version 6 | December 2015 | |
| Racing Rules of Sailing for 2017-2020 | August 2017 | |
| Racing Rules of Sailing for 2021-2024 | December 2020 | |
| Előírások | ||
| Australia | July 2017 | |
| Canada | November 2019 | |
| Great Britain - RYA has declined to grant a license for prescriptions and cases. | November 2019 | |
| New Zealand | July 2017 | |
| United States | February 2017 | |
| Esetek | ||
| World Sailing Cases | February 2022 | |
| World Sailing Q&As | March 2022 | |
| Match Race Calls | January 2020 | |
| Match Race Rapid Response Calls | October 2018 | |
| Team Race Calls | December 2018 | |
| Team Race Rapid Response Calls | February 2016 | |
| CAN Cases | October 2017 | |
| RYA Cases | November 2019 | |
| US Appeals | November 2019 | |
| Kézikönyvek | ||
| World Sailing Judges Manual | December 2019 | |
So how is the question not moot?
The Definition of Zone is giving you the answer.
"The area around a mark within a distance of three hull lenghts of the boat nearer to it"
If the boats are even the larger will take command.
a) The mark is to be rounded to port.
b) In this special "picture" both are at the same DISTANCE.
But the definition of zone is about DISTANCE.....not about which is first in its zone.
to imply that rule 18 would get turned on when the larger boat enters the bigger zone if the boats are approximately the same distance from the mark.
18.1
When Rule 18 Applies
Rule 18 applies between boats when they are required to leave a mark on the same side and at least one of them is in the zone. However, it does not apply
Perhaps more interesting is when both boats enter their individual hull length defined zones at the same time.
It seems rule 18 works!
As ever the difficulty is establishing the exact facts... But we all know the bit about late make or break overlaps.
"Perhaps more interesting is when both boats enter their individual hull length defined zones at the same time."
I believe that would simplify matters, because if two dissimilar length boats are each three of their own lengths from the mark at the same time, the smaller of the two will necessarily be closer to the mark, and in that case, the definition of zone will determine that the smaller zone applies.
Just shaking the branches here ..
We have 5 antecedent object-nouns in blue (emphasis added) .. and one pronoun "it" in orange.
If "it" refers to the "mark" .. then there can be a bit of confusion as shown by OP of which boat's length defines the zone.
If "it" refers to the "area", then the first boat to reach their zone defines the zone the boats are operating within.
Maybe the definition of "Zone" could be clearer by replacement of the pronoun with the actual noun the pronoun refers to?
Ang
PS .. a bit of very fuzzy 9th grade sentence-structure analysis below
(The) Zone (is) the area. .. is the core sentence .. Subject/Verb/Object.
Aren't all the rest prepositional phrases? "... around a mark / within a distance / of three hull lengths / of the boat / nearer to it."
So, doesn't the pronoun default to refer to either the subject or the object of the sentence they follow? .... and not the previous prepositional phrase's object? If we say that the pronoun refers to the prepositional phrase object that precedes the pronoun, then "it" would refer to "hull lengths" or "boat" or "distance" (which doesn't make sense).
Maybe this is a stronger grammatical case that "it" refers to "area" or "zone" (which are equated to each other by "is", so the same thing) and not "mark"?
If someone is fresher on this (or is or knows an English teacher), feel free to take me to the carpet.
As to Angelo's sentence deconstruction argument that 'it' refers to the area, I like it and it does resolve the ambiguity. I'll ask my daughter when she wakes up, after all I just spent a small fortune getting her a writing degree :-D.
(edit) After giving me the 'you're crazy Dad' look, she says it goes back to the closest thing that makes sense. I.e. first is 'boat' which makes no sense, next is 'mark' so that is what 'it' is.
Alas, an area defined by some object's proximity to that area makes no sense - and is even harder to "eyeball" on the water than proximity to the mark.
So "it" must refer to the mark.
Sure it can make sense .. and we are all eyeballing the extents of this each time we approach a mark with boats in close proximity to us.
In either case .. "it" refers to the 3BL "area" or "it" refers to "mark", boats are required to "eyeball" the 3BL zone based upon their boat's length as well as based upon the BL's of boats around them .. and at the same time judge when boats are inside or outside those areas .. and thus their proximity to them.
As seen in the OP, if we assume "it" refers to "mark" and if you are a smaller boat and a larger boat is closer to the mark, then you have to calculate when that boat reaches the 3BL zone based upon her length, not yours.
If it refers to the "area" .. you also have to calculate when that boat reaches the 3BL zone based upon her length, not yours.
Therefore, both interpretations require the same degree of mental exercise .. if "it" is the "mark" or the "area".
Neither one is harder to "eyeball"
I think there may even be a more perverse scenario where the larger boat overtakes the smaller boat and becomes the closer boat after she is inside of her own circle but before reaching the smaller boats circle. Would the definition of then prevent the possibility of either boat being at the 3-length zone at any point in time and thus eliminating part b? I would argue not in that the boats moving forward into the Zone or the Zone magically growing at inflationary speed would have the same effect that when the first one entered it locked in the rights of the inside boat.
reductio ad absurdum at its finest.
The scenario is a good example of why it's not a great idea to have widely disparate boats on the same course at the same time.
When we consider why we have a "zone" in the first place .. the zone is there for safety .. and we went from 2 to 3 BL's for the zone because boats were getting faster and needed more time to maneuver safely.
Seems to me if we had our druthers, we would want the larger boats to have their full 3BL zone for safety reasons Also, I think for clarity and safety reasons, it should be absolutely clear that's what controls. At first blush, I think a "first to their zone" approach would accomplish that, but there might be better ways to spell it out in the definition as well.
So .. what do you all think about this?...,
The definition of Zone could be simplified by removing the phrase "nearer to it".
.. so now we've made it so that each boat has a zone which is based upon their HL.
Now we make a slight change to RRS18.1
So .. I think with this change we clearly establish that each boat has a zone based upon their HL and that 18 turns on when the first of them reaches their zone. The result for boats of disparate HL's would be that the larger boat defines the zone.
As always when I play with the rules like this, I invite and encourage anyone to take whacks at it.There are really 2 questions ..
- do we feel it's better for the for larger boat's zone to control?
- do my slight mods accomplish that?
- AngThe only way a judgement must be difficult is if Blue boat reached the Blue line at the exact same time that Red boat reached the Red line. However to see all of this with precision is impossible even if the judge has video of the rounding. Boats this close seem to have overlap in any case.
A proper answer to Catalan's question "which zone must I consider? might be "The zone defined by the boat nearer to the mark", and might be further amplified by saying 'On the evidence presented, neither boat has reached the zone, and no rule has been broken'.
It would probably have been more useful if Catalan's scenario had been expanded by showing 'what happened next', with an indication of what a boat might have protested for. The obvious example would be for Red to then luff Blue away from the mark to enable Red to bear away and reach the zone first clear ahead, with mark-room.
That scenario would give us, as judges, an issue to discuss.
I agree with Phil Hubbell and John Mooney that, in most cases, which 'zone boundary' is applicable is likely to be of little relevance to concluding whether rule 18 applies. It might, however, be relevant to precisely when rule 18 begins to apply.
On Catalan's scenario, if both boats advance by a small increment, then either one draws ahead of the other and the issue of which boat is nearer the mark is resolved, or else they remain exactly equal distances from the mark, and this provides a degenerate application of the definition of zone which fails.to unambiguously identify the zone. It is highly unlikely that a protest committee would find a fact that boats were exactly equal distanced from the mark. The protest committee would, most probably apply the Last Point of Certainty principle to resolve the issue.
It might be that the protest committee found as a fact that Blue, the larger boat, was not nearer the mark when the boats reached the larger zone defined by B's hull length, but became nearer the mark after reaching the larger zone boundary, but before reaching the smaller zone defined by Red's hull length.
In that case, it will be impossible to identify ‘the first of them [to] reach … the zone’, and thus rule 18.2( b ) (and therefore also rule 18.2( c )) cannot apply: the applicable rule is rule 18.2( a ).
The only way this would make any practical difference is in light wind conditions with strong tide or current so that B might move into a position not overlapped outside Y, where the ‘enduring’ mark-room that would have been available under rule 18.2( c ) is not applicable.
In answer to Angelo's grammar question, it is a rule of grammar and statutory interpretation that a pronoun is usually taken to refer to the noun nearest to it. The Definition of mark is unambiguous, except in the degenerate case of exact equality of distance identified by Catalan, and is in no need of amendment.
I thought of another possible interesting peculiarity of the "it = mark" interpretation this morning ...
If "it" = "mark", then the size of the zone can change while 2 boats are inside it, based upon which boat is closest to the mark at any point in time.
Examining the Zone definition as we now have .. and looking at RRS 18 .. I don't see anything which freezes the zone's size once established (when "it" = "mark").
This could have interesting implications for RRS 18.3 interpretations. In one of our previous threads, we explored when RRS 183's limitations cease ... When Does RRS 18.3's Limitations Cease?
So, 2 boats of disparate sizes .. one in front of the other .. seems one could argue that the zone is based on the BL of the boat that is ahead as they approach and based upon the BL of the boat that is behind as they leave the mark behind.
So, seems that's another benefit of the "it" = "area" interpretation (or my Zone-Def/RRS 18 mod) is that the zone's size is set to the larger boat's size and stays that size (is set) while the larger boat is still in the zone.
Ang
There are simply too many nouns preceding the pronoun "it" to be clear and the brevity of using "it" in this instance seems unnecessary.as the word "it" saves only one syllable ("it" vs "the mark")..
If the intent is that "it" refers to "the mark", IMO, the def should be mod'd as such as it costs so little and clarifies so much. - Ang
I think that this will become more and more an issue going forward as local regions and YC's try to entice participation by adding more "Corinthian" events.
I don't know what others are seeing around the world, but here in the Chesapeake Bay, people are finding harder to find time for racing sailboats that are not OD's (mainly PHRF) .. numbers are way down and the solution has been to create more races that are inviting to the very infrequent and casual racer and to create "fun" racing formats like the pursuit start.
Also, as fewer and fewer handicap boats show up, RC are having to combine fleets to get reasonable numbers .. maybe combining/collapsing PHRF fleets into fewer divisions.
You take those items .. an open Corinthian event, fewer handicap fleets, very occasional racers, and a pursuit start .. you are putting together an event where boats of very different sizes and speeds are going to converge at marks by design .. with folks at the helm that are going to need every bit of that 3HL's.
Even in events that are not pursuit-starts .. it is not uncommon for an RC to set a longer course for the faster fleets and subsequently setting shorter courses for fleets to follow. This has the same effect of mixing of big-fast boats and smaller-slower boats at final roundings.
In the end, with all these considerations, I think it would be best for safety and clarity that the zone's size is defined by the larger boat's HL .. however that is done.
Also, if Blue reaches the blue line at the same time that Red reaches the red line, judgement couldn't be easier. Red is closer to the mark, and it is three of her lengths that define the zone. She has entered it, and Blue has not.
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John Allen, I agree with most of your post (especially the observation that without a complete scenario, we are left posing the questions we answer, rather than working on a specific problem), but I'm puzzled by this section of it:
"...or else they remain exactly equal distances from the mark, and this provides a degenerate application of the definition of zone which fails.to unambiguously identify the zone....
It might be that the protest committee found as a fact that Blue, the larger boat, was not nearer the mark when the boats reached the larger zone defined by B's hull length, but became nearer the mark after reaching the larger zone boundary, but before reaching the smaller zone defined by Red's hull length.
In that case, it will be impossible to identify ‘the first of them [to] reach … the zone’, and thus..."
I think I understand what you mean by a degenerate application of the definition of zone, in that it doesn't work while the two boats are equidistant from the mark. As long as that's true, I agree that 18.2b & c can't apply, and we must rely on 18.2a. I also agree that the jury should apply the principle of the last point of certainty (and I think they are encouraged to do so by the text of 18.2e, which applies the same principle to the question of whether or not a boat has established or broken an overlap).
However, 18.2a doesn't help us know precisely when the entitlement to mark room begins, and I think I disagree that the scenario you describe above makes it impossible to identify the first boat to reach the zone. I think your answer attempts to avoid dealing with the fact that the size of the zone changes when the length of the boat nearest to it changes, and while a stable zone size might be valuable (more about that in my answer to Angelo, below), I don't see support for solving that problem in the text. It seems to me that in your scenario, the first time the boats reach the zone is at the moment that Blue gets nearer to the mark than Red, and while that may be unstable, I don't think it's ambiguous, so I question the assertion that the scenario creates a "degenerate case" (I may be misunderstanding your use of that term).
It might be more accurate to say that the zone had expanded to reach the boats then, but I think the definition says they are in the zone at that moment, and have not been before that. As long as she is not prevented by Rule 17, I believe Red can luff Blue as she pleases (subject to the limitations of 16.1) up to that point, but as soon as Blue gets nearer to the mark (or they reach three of Red's lengths from it), they are in the zone and Red must curtail her luff and give Blue the room to which she is entitled (unless we can be sure Red has broken the overlap in the interim).
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Angelo, I understand your point about the proliferation of circumstances in which boats of disparate sizes and marginal understanding of the rules might find themselves approaching the same mark, but while I honor your attempt to simplify the rules, I respectfully submit that this is a case in which such an attempt to simplify makes the problem worse, not better.
First, I think that for the grammatical reasons John A has noted, it's pretty clear that the "it" in the definition of zone is the mark, not the zone itself. Parsing the definition any other way not only violates those conventions, but creates a circularity in the definition that introduces more confusion than it solves.
Second, I must strenuously disagree that safety and clarity would be served by defining the zone using the larger boats' lengths. To the contrary, I believe that the more disparate the sizes, speeds, and skill levels become, the more important it is to have the zone adapt to the size of the nearer boat. If we have 50-footers and Optis approaching a mark at the same time, the Optis would find themselves in a zone that has a radius of 150', which would be almost 20 of their own lengths, not three. If you think sailors have trouble determining when they are three lengths from a mark (and we know that even experienced competitors regularly do), just imagine their ability to determine accurately what 20 lengths looks like! Even more confusing, since the entitlement to room is a matter between two individual boats at a time, smaller boats might well find themselves having to determine the sizes of several different zones defined by the lengths of boats behind them, and then figure out the interplay of rights and obligations those different-sized zones created for them, and the tactical considerations those rights and obligations imposed. That would create an impossible situation for the smaller boats, forcing them to perform multiple complex calculations that require them to look back and determine the sizes of boats behind them in order to know what their rights, obligations, and best tactical moves are, all while contending with the challenges of an impending mark rounding and steering a moving boat through a crowd so as not to hit anyone. If you "solved" that problem by saying the largest boat approaching the zone at any given time is the one that defines the size of the zone, you would first have to figure out when a boat started "approaching the zone", and even if you figured that out, you might well have an Opti and a Laser, or an Ensign and a 49er duking it out in a 150' zone. I submit that it's completely unworkable, and the confusion would lead to far more dangerous mark roundings.
By contrast, under the present situation, sailors have to know what three of their own lengths looks like on the water, and they don't have to look behind them while approaching a crowded mark to know what to do. Overtaking boats which are larger and faster carry additional burdens to be careful about sticking their noses into situations they can't get out of, and to be careful not to run down smaller, more maneuverable boats ahead of them, but that's consistent with other rules about overtaking boats, and I submit that those burdens are a feature, not a bug.
Like I privately said recently to another respected forum-poster ... "It's hard to sharpen a knife rubbing it against putty".
Still, given the consensus is that "it" must mean "mark" .. I can see little reason not to replace "it" with "the mark" in a future RRS revision.
Ang
said
John AllenAllan, I agree with most of your post (especially the observation that without a complete scenario, we are left posing the questions we answer, rather than working on a specific problem), but I'm puzzled by this section of it:
"...or else they remain exactly equal distances from the mark, and this provides a degenerate application of the definition of zone which fails.to unambiguously identify the zone....
It might be that the protest committee found as a fact that Blue, the larger boat, was not nearer the mark when the boats reached the larger zone defined by B's hull length, but became nearer the mark after reaching the larger zone boundary, but before reaching the smaller zone defined by Red's hull length.
Let me expand.
Red, the smaller boat reaches the (larger) Blue zone boundary as defined by the hull length of Blue, ahead of Blue: Red is thus nearer the mark, 'the zone' is defined by Red's hull length, and Red has not yet reached that zone.
No boat is in 'the zone', and rule 18 does not apply (rule 18.1).
Before Red reaches the (smaller) Red zone boundary, Blue, travelling faster, advances her bow ahead of Red. Blue is now nearer the mark, and 'the zone' instantaneously changes to that defined by Blue's hull length, the boundary of which, both boats have already passed..
In that case, it will be impossible to identify ‘the first of them [to] reach … the zone’, and thus..."
OK, you have me: Red was the first of the boats to reach the boundary of the Blue zone, boats were overlapped and rule 18.2( b ) applies. I was wrong to go for for rule 18.2( a ).
However, 18.2a doesn't help us know precisely when the entitlement to mark room begins,
Agree it doesn't.
What does let us know precisely is when rule 18, as a whole begins to apply, namely, when one of the boats is in 'the zone'. This occurs the instant Blue becomes Bow out on Red, and the zone boundary switches to the Blue zone: at that point, rule 18 applies and (regardless of whether it's 18.2( a ) or ( b ), the boat overlapped inside (Blue) becomes entitled to mark-room.
and I think I disagree that the scenario you describe above makes it impossible to identify the first boat to reach the zone.
You're right. See above.
I think your answer attempts to avoid dealing with the fact that the size of the zone changes when the length of the boat nearest to it changes, and while a stable zone size might be valuable (more about that in my answer to Angelo, below), I don't see support for solving that problem in the text.
Or I just went searching for a 'smart' answer.
It seems to me that in your scenario, the first time the boats reach the zone is at the moment that Blue gets nearer to the mark than Red,
I disagree with this. The moment Blue gets nearer the mark than Red is the moment the zone switches to the Blue zone (the boundary of which they have both already reached), and at which rule 18 begins to apply, one boat being in 'the zone'. Once 'the zone' is clearly defined as having become the Blue zone, then it is a simple fact found to state that Red had reached 'the zone' first (even though, at that time, rule 18 did not apply, because 'the zone' at that time was the Red zone).
In other words, 'the zone' becomes retrospectively defined to be the Blue zone, after the boats have reached the Blue zone boundary, at the instant that Blue becomes nearer the mark.
and while that may be unstable, I don't think it's ambiguous,
I agree, as long as one of the boats is nearer the mark, there is no ambiguity.
so I question the assertion that the scenario creates a "degenerate case" (I may be misunderstanding your use of that term).
The 'degenerate case' only applies when boats are exactly equal in distance to the mark.
It might be more accurate to say that the zone had expanded to reach the boats then, but I think the definition says they are in the zone at that moment, and have not been before that. As long as she is not prevented by Rule 17, I believe Red can luff Blue as she pleases (subject to the limitations of 16.1) up to that point, but as soon as Blue gets nearer to the mark (or they reach three of Red's lengths from it), they are in the zone and Red must curtail her luff and give Blue the room to which she is entitled (unless we can be sure Red has broken the overlap in the interim).
Yes, but we shouldn't be using pre-1995 language to say so.
So, in a RRS 18.3 scenario with an offset mark and boats of disparate sizes, the zone-size would be based on the port-tacker's HL who tacks inside the zone ahead of a starboard tacker, but as they pass the mark, the mark would change to the HL of the boat behind?
Interesting in John M's and others thoughts on this too. - Ang
I thought about this some more and decided to see if I could figure out what the perspective would look like from two different boats. I tried to draw them entering the Larger boats zone at the roughly the same time and maintain about that same distance. The tool was quite helpful in taking the same tracks but adjusting the Zone point of view between a keelboat and a laser. Other than the Laser showing blatant disregard to personal safety and then getting wise how would you call this exchange?
I think there may even be a more perverse scenario where the larger boat overtakes the smaller boat and becomes the closer boat after she is inside of her own circle but before reaching the smaller boats circle. Would the definition of then prevent the possibility of either boat being at the 3-length zone at any point in time and thus eliminating part b? I would argue not in that the boats moving forward into the Zone or the Zone magically growing at inflationary speed would have the same effect that when the first one entered it locked in the rights of the inside boat.
reductio ad absurdum at its finest.
That said and as one who appreciates taking things to their extremes to explore bounds, a more likely scenario would be a newer mid-20' sportboat and maybe an older larger racer/cruiser (like a J35 or some older IOR in the 35-40 range), which could have close PHRF ratings and thus in the same fleet. In that case, the larger boat's zone to round would be reduced to a 2HL.
said Yes. The size of the zone can change with different sized boats depending on which boat is nearer to the mark. I can't see any other way of construing the definition of zone. It may well be that in a rounding or passing manoeuvre, the boat nearer the mark, and hence the size of the zone will change, but ISTM that in any realistic scenario, both boats will still be within the zone, whichever size it is.
Can you set out in some more detail, maybe with a diagram, how you think this could be a problem?
Unless you are using some bizarre 2000 SI, a windward mark with an offset are just two marks. The boat leading around the first mark, will be the boat nearer the second mark will she not?
Again, can you set up a concrete scenario where you think there could be a problem?
said I can't help taking your later point first. Why do you say that the Laser is 'showing blatant disregard to personal safety'?
A boat is entitled to expect that another boat will another boat will comply with the rules (Cases 3, 87).
Myself and other posters have touched on the 'evidential' difficulties of a protest committee ever being satisfied that boats, at any particular time, are exactly equal distances from the mark, and I suggest that your diagrams illustrate this point.
At position 1, Blue is bow out on Yellow, and nearer the mark.
At position 3, Blue is bow out on Yellow, and nearer the mark.
I would suggest that most protest committees are going to accept the inference that at position 2 Blue is also bow out and nearer the mark, or at lest not find, on the balance of probability, that at position 2, Yellow is nearer the mark.
I think that a protest committee, hearing a valid protest, would find that Blue was nearer the mark at positions 1, 2 and 3, and when she reached the zone defined by her hull length, and that she reached that zone first, and conclude that:
- Yellow was not entitled to mark-room.
- At position 3 + delta, Yellow did not keep clear of Blue and broke rule 11.
- At position 3 + delta delta, Blue was the first boat to reach the zone, Yellow became required to give Blue mark-room in accordance with rule 18.2b, and did not do so. Yellow broke rule 18.2b.
- Assuming that there was no contact causing injury or damage, Blue broke no rule
Decision: Penalise Yellow.The analysis obviously changes if Yellow is bow out on Blue at position 1, position 2 - delta, and position 2, so that Yellow is nearer the mark, and reaches the zone defined by her hull length at position 2 - delta first, so that Blue was required to give Yellow mark-room in accordance with rule 18.2b, from the time Yellow reached the zone, and thereafter. In that case, I think the conclusions are:
- Yellow became entitled to mark-room in accorcance with rule 18.2b at position 2-delta.
- At position 3 + delta, Yellow did not keep clear of Blue and broke rule 11
- At position 3 + delta, Yellow sailing within the mark-room to which she was entitled, and shall be exonerated for breaking rule 11 in accordance with rule 21a
- At position 3 + delta Blue did not give Yellow mark-room. Blue broke rule 18.2b.
Decision: Penalise BlueThe last two conclusions are arguable :
- Maybe Yellow was sailing to a point away from the mark, making a tactical rounding, and sailing outside the mark-room to which she was entitled, and
- ,Given that Yellow did not appear to respond to Blue's luff, and continued to sail an advantageous course, maybe Blue did, by bearing away after position 3, give Yellow mark-room.
Those would be issues that a protest committee would resolve by finding some facts about conditions, times and distances. Again, I can't see why these applications of the rules are 'perverse'.I discussed the situation where Large, behind Small's bow when Small reaches the zone defined by Large's hull length, draws ahead of Small, before reaching the zone defined by Small's hull length in a previous post Created at .Created: Tue 00:44.
In that case:
- boats were overlapped when the first of them (which happened to be Small) reached 'the zone', and the boat overlapped inside, namely Large, is entitle to mark-room in accordance with rule 18.2b.
In a post before that, I flirted with the idea that because the zone might have been ambiguously defined, it was not possible to identify any boat that was the 'first of them to reach the zone', and thus that rule 18.2b could not apply, leaving only rule 18.2a. On reflection, I abandoned that idea, in favour of the analysis above.
Thanks John. At this point I'm satisfied with the new interesting insights that I've gained regarding the Zone's dynamic size definition .. which really hadn't dawned on me until the analysis fostered in this thread. - Ang
PS .. FWIW ... Without redrawing the boats and zones, I'm thinking about the image that I used in my When does RRS 18.3's Limitations Cease post .. and the intellectual-realization (as academic as that might end-up being) that an RRS18.3 luff-limited boat (Blue) is being controlled by the zone based upon trailing boat's HL (Yellow), which could be a different sized zone than defined her "tack in the zone" maneuver .. that's all.
B is nearer to M1 from @1 to @3-delta. B is nearer to M1a throughout.
The zone boundary of M1a is accurate as illustrated based on B's hull length throughout.
The zone boundary of M1,illustrated, based on B's hull length is accurate up to the point that Y, trailing B, becomes nearer M1 than B, about @3-delta. At that time, weird as it may seem, 'the zone' around M1 instantly expands to become based on the larger hull length of Y.
That would put the new zone of M1 out to about @4
B's hard luff @4, is still within the zone of M1, B is still bound by rule 18.3, and if she causes Y to sail above close hauled, she breaks rule 18.3. No change to the analysis in the other thread.
So, the lesson learned for Blue (assuming Blue is significantly smaller than Yellow) is that she is limited by larger zone than limited her on the way into the mark. If Blue thought she could luff up as soon as Yellow exited Blue's smaller zone, she would have fouled Yellow. I would bet this is not intuitive to most sailors.
Also, large size differences aren't just hypothetical ....
When I had my '77 Pearson 10M (PHRF 156 so usually C-fleet, but sometimes B) .. I very often competed against a Henderson SR-Max 21 (PHRF 174). In A fleet in the Chesapeake we have a very well sailed Antrim 27 (PHRF 84) .. squarely in the A fleet against 35'-40' boats.
These zone size differences can be significant.
the event of disagreement as to whether an action takes place inside or outside of the zone. In the absence of jury boats, how is the decision adjudicated?
I believe that with no positive proof the decision 8s based on the last known certainty?