Blue owes Red mark room, but mark room does not entitled Red to push Blue down. There was still plenty of time for Blue to give Red room and no indication that she would not have done so.

Red DSQ for breaking 11 as Windward boat she did not keep clear.

Blue, leeward, had Right of Way, but owed Red, Windward boat, mark room.
Blue broke 18.2b, and 14
Red broke 11 and 14, but is exonerated under 43.1b
Blue is DSQ.

The two RC boats became entangled and lost places. As a result, under Appendix E, Radio Sailing, definition of "disabled", a boat is disabled while she is unable to continue in the heat, and as applied in RC racing, Appendix E 6.6 supplements RRS 62.1 with (f) which gives a disabled boat the right to request redress.

Note: if Red was unable to finish as a result of being disabled, Blue must retire. E.4.3.c

From looking at the diagram, it does not look like there was enough room for red to sail to and at the mark round the mark. (No facts were found/stated so I’m just looking at the diagram) Once the overlap was established at the zone red is entitled to mark room. Blue had at least a boat length to give her that room. 
Red broke 11 but is exonerated since she was sailing within the room she was entitled to.  Blue broke 18 and is dsq 

I'm inclined to agree with Greg here. There is still lots of time for Blue to give mark room to red. Meanwhile, Red must keep clear.

Red was overlapped very close to Windward, so much so that a slight turn down at the zone caused contact. If Blue had tried to turn down at the zone, her stern would likely have hit red. Red was probably not keeping clear before the zone and definitely not at the zone.

No evidence that blue would not have let red sail to the mark and round it.

Mark-Room Room for a boat to leave a mark on the required side. Also,

(a)room to sail to the mark when her proper course is to sail close to it, and

(b)room to round or pass the mark as necessary to sail the coursewithout touching the mark

Room The space a boat needs in the existing conditions, including space to comply with her obligations under the rules of Part 2 and rule 31, while maneuvering promptly in a seamanlike way.

Greg and Nicholas, once in the zone , red is entitled to mark room to comply with rule 31, which according to the diagram, she needed to turn down slightly to clear the mark. Blue had a boat length of time to turn down to give her this room and failed to do so.   

Room has to a be given, as soon as mark room is established which is at the zone in this case. Case 75 notes the concept of a notional corridor of space from the point where mark room is established to a position next to the mark as mentioned in the definition.  If red stays within this corridor then they are sailing within the room to which they are entitled and if blue does not give them room to do so they infringe rule 18.  Red might technically break rule 11 but is exonerated.  The key take away is that blue can’t luff for a boatlength and then bear away hard to give red room at the mark in the last boatlength or two.  It’s not “room at the mark” it’s “mark room” with all the multiple requirements found in the definition.  If Red turns down outside the corridor, then rule 11 is fair game and exoneration for red is lost.

The fact had blue set up for a close rounding so that sounds like a fact that they are not giving red room to do that close rounding.  I’d conclude the bear away by red at 2 was still in the corridor so I’d penalize blue.
I agree with Tim OConnell.

If Blue was luffing, then I would agree that she was not giving Red room to sail to the mark.

However, Blue was not luffing and had only just entered the zone, so rule 18 had only just switched on.  Prior to that, Blue is under no obligation to sail deep to allow Red a direct run to the mark.
The fact that contact happened at the zone suggests that Red was too close to Blue immediately prior to entering the zone. i.e. when Blue was an inch outside of the zone, Red must have been an inch away from hitting Blue, so that contact happens at the zone.  Red was not keeping clear before the zone.

With regards to the notional corridor, for Red to have hit Blue just after the Zone, she was not sailing to the mark, but was sailing to some distance away from the mark.  From the diagram, if you extend Red's course you see that she is heading to more than a boat width away from the mark:
 

Red is not sailing within the mark room to which she is entitled.  She has broken both 11 and 14.

If Red was keeping clear before the zone, then altered course to sail to the mark (and no more), then contact would have occured well within the zone.   Unless Blue is actively luffing, I cannot see how she can break 18 when she has only just entered the zone.

Blue has been in the zone for more than a boat length.  (More than 1/3rd of the way to the mark.)  She owes mark room. The drawing would put red between 1/4 and 1/3rd of a boat width from the mark. To me, that is not taking more than the entitled room. Blue, as soon as the she enters the zone, owes red mark room.  She had more than a boat length to give it and did not alter course to provide it.  She did not provide mark room at her own risk. 

IMO if Red stays within this corridor, she is sailing within the MR she is entitled to. 

Blue is not obligated to give mark room until position 2. But she is hit at position 2. Blue had not been it zone for a boat length, she had just entered it.

She can't turn down because Red's bow is next to her transom. The only way out for Blue is teleportation

If you believe blue broke 18, then that is a no way out situation unless Blue starts giving mark room before the zone. 

I still maintain that at 3BL, blue had done nothing to prevent red from sailing to the mark.

Greg, the OP drawing did not show the 4BL zone for RC’s, but the OP describes the overlap existed at the zone.  So we either assume @ #1, Blue’s bow just crossed the zone (and the drawing is off) or my drawing shows 4BL, and the overlap existed 1/2 BL before #1.  

Either way, Blue owes Red MR at #1, if not slightly before. 

Greg W, Blue is obligated at 1. The radio sailing zone is 4BL. Even if it were 3 BL's, as soon as blue's bow crosses the zone while red has an inside overlap, blue must give mark room, immediately, not when blue feels like it, or later. It can't be any surprise to blue that they needed to bear off to make room. Blue can't keep on sailing directly to the mark because as drawn, they are sailing a course that squeezes red out of their entitlement to mark room. In my findings, I think both boats could easily have avoided contact earlier, and since they didn't take action, they both broke 14. As keep clear windward boat, red's contact means she also broke 11. Red's infractions don't eliminate blue's initial obligation to give mark room. Since blue didn't give mark room, blue is stuck with their infractions, and because red only broke the rules because of blue, red is exonerated. QED.

Angelo:  "Blue owes Red MR at #1, if not slightly before. "

#1 is the point where the overlap is established, and rule 18 comes into play.  Blue does not need to anticipate that Red will have an overlap and provide room at or prior to #1.

Tim, Angelo,.  Ah didn't realize the RC zone starts at 4BL, so yeah Blue owed room and should have started turning down.

I still think there is an issue with how far down Red is pointing, as she is steering well clear of the mark, even though she is in the "corridor". But a boat owed mark room does not need to give the ROW boat time and opportunity to give that room, so i guess that aggressive turn down is ok....   But a ROW boat can't turn aggressively like that in close quarters, so i don't see that a boat owed room should be able to either. So really should find a way to DSQ Red for it, else an inside boat can basically hit the outside boat with impunity.

Is Blue sure there wasn't damage?

Is sailing at that course really sailing to the mark? Hmmm if not then Blue is ok. Really need to DSQ them both somehow. Is Red sure there was not damage?

Thanks

Tim:  "Even if it were 3 BL's, as soon as blue's bow crosses the zone while red has an inside overlap, blue must give mark room, immediately, not when blue feels like it, or later. "

At #2 (3BL), what are the obligations on Blue?

R18.2(a) When boats are overlapped the outside boat shall give the inside boat mark-room
Definition:  Mark-Room.  Room for a boat to leave a mark on the required side. 

At #2 (3BL) can it be stated as fact that Blue has failed to allow Red to leave the mark on the required side?  

Greig, at #2, blue is still required to give mark room. The definition of mark room, also includes the defined word "room" therefore the we need to look at its definition too which is: the space a boat needs in the existing conditions, including space to comply with her obligations under the rules of Part 2 including Rule 31, while manoeuvring promptly is a seamanlike way. Red appears to have to adopted that heading in order to make a seamanlike rounding i.e. some wiggle room to actually turn around the mark without hitting it.. Blue, still pointing directly at the mark, and on a course tight to it, appears to be cutting across Red, and in my opinion of the diagram, is not giving in, and is restricting red's mark room to do a seamanlike rounding. Even if red also pointed directly at the mark, blue and red would continue to make contact, therefore another indication that blue is failing to give room.

There's another consideration in the spirit behind applying the RRS in Radio Control sailing, including Appendix E: i.e. you can't always get an absolutely accurate view from a vantage point on the dock of relative headings and positions. This is particularly true when you are looking downwind at a leeward mark with boats' sails between you and your own boat, and the mark. As a result, an obligated boat needs to really make sure that they are keeping clear and or giving room, i.e. sailing a bit less aggressively, particularly at mark roundings, and that failing to do that often ends in boats getting tangled. That's one of the slowest ways to win a RC race !!! 

Taking a downwind mark a few boat widths wide is not for a seamanship rounding, but for a tactical rounding: in wide and out high.  Mark room does not include room for a tactical rounding. Only to sail to the mark and to round it in a seaman like way. Often this can mean overshooting the mark a little bit it coming out in a low upwind lane... both bad tactically, but not due by mark room.

Now an outside boat may choose to give more room so that both boats can make a tactical rounding, but that is not compelled by the rules.

I get it that angles are hard to judge from the shore ( they are hard enough to judge on the water), but surely any resulting leniency applies equally to Red as it does to Blue.   I.e is Red really sure she is sailing to the mark and not at some distance from it. If you expect Blue to give some extra room just in case she had got the angle wrong, then Red equally needs to not take too much room at 3BLs as she might have the angle wrong.

Regardless, it is the PCs job to find facts and if that diagram represents the accepted facts found, then Red is not sailing to the mark, but is sailing for a tactical rounding wide of the mark.

It's a close call, but on that diagram I'd DSQ Red not blue.

If Red's heading was too the mark, then contact would have been at 2BL or 1BL.. In that case if Blue had not altered course it would be clear she had not given room and I'd DSQ Blue.

Greg, we'll have to agree to disagree. Red's course isn't a few boat widths wide, perhaps 1.5 when extending a heading, nor tactical at that point. The bottom line is that Blue owed mark room from #1 and did nothing to alter course to the mark, or show any sign at that time, that mark room was being given. In consideration of what would be seamanlike, we'd normally ask for information on conditions e.g. waves, wind, gusts, current, type of boat etc... Unfortunately we don't have that but to me, being pinched in towards the mark by the outside boat which clearly owes room, while still overlapped within less than 1/4 of a boat width apart, (and assuming they're approaching at the same speed) gives red little room to any rounding that would not result in further contact. We do have the facts that the boats became entangled. That in itself supports a conclusion that room was not given. Moving right along..... I have nothing further to add. Greg, I'm curious, do you sail RC boats?

Tim:  "The definition of mark room, also includes the defined word "room" therefore the we need to look at its definition too which is: the space a boat needs in the existing conditions, including space to comply with her obligations under the rules of Part 2 including Rule 31, while manoeuvring promptly is a seamanlike way."

The contact occurred at 3BL from the mark.  So are we all agreeing that at 3BL it is NOT POSSIBLE that Blue can thereafter provide mark room so that Red can maneouvre in a seamanlike way to leave the mark on the required side ?

In another very recent discussion on this forum ("Rule 20: obligation of the hailing boat after responding "You tack"), it is generally agreed that a boat that must make a near 90 degree course change 1/2 of a BL from the ROW boat, CAN be executed in a seamanlike way. 

In this case Blue and Red need only make a 10 degree course adjustment over a distance of 3BL to satisfy the requirements of giving mark room..   

I am sensing inconsistency in the definition of what is considered possible seamanlike maneouvres in RC boats.

Tim,. I don't sail RC boats so my opinion is probably very influenced by the 30 to 40 foot boats i race and the club sailing i help administer.

Happy to disagree, because this is a close. 

If i was called in to be on the protest committee on a Tuesday night after this happened on the weekend, then I'd be pissed off at both boats. Blue should definitely have started to do something to indicate she was giving took, but Red should not have made contact 3BLs from the mark. 

Blue is being slow to act, but Red is being too aggressive and forcing the issue long before she needs to.

If contact was made at the mark, then i think Red would have done everything she could to avoid contact... However, i tell my fleet in rules training that in such situations they'd be better off hitting the mark rather than the other boat. If the mark is touching one gunnel and the outside boat is touching the other, then it's clear that room was not given.

Maybe RC boats don't mind contact as much?
My bias is very much towards discouraging contact... hence I'm looking at Red for forcing contact when it's not yet clear if Blue was giving room or not.


Cheers

Greig: “#1 is the point where the overlap is established, and rule 18 comes into play.”

Then in your OP …

“At the 4BL zone Red has a slight overlap”

So, we have a bit of a conflict in your scenario.  “Has a slight overlap” or “overlap was established” at the zone.

If you are saying that at the VERY INSTANT that Blue’s bow reaches the 4BL zone that “the overlap is established”, it would likely be assumed that the overlap did not happen under 18.2(e).

What I did is take your drawing and I drew the 4BL circle based upon the boats used in the diagram.  Doing that,  at #1 Blue is ~ 1/2 BL inside the zone.  This allows us to say that Red established overlapped prior to Blue reaching the zone and 18.2(e) is not at play … and “at the 4BL zone Red has a slight overlap” (from your OP). 

As soon as Blue’s bow reaches the zone, either at #1 or 1/2 BL before #1, Blue is obligated make room for Red, which is a corridor directly to the proper side of the mark.   The width of that corridor changes based upon the characteristics and speed of the boat owed room and the conditions at hand. 

Generally that’s between 1.5-2 boat widths at a min (IMO).  I’ve heard other very respected judges say that it’s up to 1BL wide. 

Blue did not make any change in her course at #1. That’s the issue. 

Angelo,

No I'm not saying that and I do not think this issue depends on if or when the overlap was established.   The agreed facts are that the overlap was established at the zone, so I assume that there is no doubt about that, else Blue would be saying it had not and we'd have to wind back until there was no doubt.

What I'm saying INSTANTLY happens as the first of the boats reaches the zone, is that rule 18 turns on.   Prior to the zone, Blue does not owe Red mark room and is at least entitled to sail her proper course or (depending on how the overlap was established) perhaps entitled to luff Red.

Prior to the zone, Blue is under no obligations to sail down to give Red room to sail to the mark.  So it is only at the Zone that Blue has to start thinking about letting Red sail to the zone, but by that time, Red has put her bow very close to Blue's quarter, so Blue will not be able to change course easily without making contact.  A lot depends on the conditions, but an argument could be made that Red was too close before the zone and thus broke 11 before 18 came into play. Certainly as Red sailed towards Blue, it reduced Blue's ability to turn away without making immediate contact.

I totally agree that as soon as Blue reaches the zone she must allow Red to sail to the mark.   I understand that a corridor concept has been used to illustrate what that means, but that is not the wording of the definition of mark-room.  The definition says that Blue must allow Red to sail to the mark and round it. If Red is in the corridor, but her heading is not towards the mark, then I don't believe she is sailing to the mark just by being in the corridor.  Here heading at #2 is taking her out of that corridor (and into the gunnels of Blue), so I do not believe she is sailing to the mark.    She is sailing to a point wide of the mark.  Blue is under no obligation to allow her to do that.

If Red had not turned so aggressively, would there have been contact?    I think yes, but only if Blue did not later alter course.  If Blue altered course at 3BL or 2BL I think Red could have sailed directly to the mark without contact.

Basically I think Red forced the issue too early by turning too early. 

 

Greg, you raise an interesting issue: what is the relevance of the course heading of the boat with mark room.  I would argue it is not relevant and would suggest that the relevant questions are.
1. Is the boat with mark room sailing within the room to which they are entitled.
2. Has the give room boat given the room they are required to.
I believe this rule is about where the boats are and where they move to and not about what direction they point or where they might end up if they point in a certain direction.  If you don’t like where they are pointing, i think you have to wait to see where they actually go. E.g. do they actually sail outside the corridor.
When you say a corridor has been mentioned but is not the wording of the rule I think you are misunderstanding the meaning of “authoritative interpretations” which is what WS cases are.  They are equivalent to rules.  They have interpreted the meaning of “room to sail to the mark” as being a corridor to close to the mark for a two boat situation and so that is now equivalent to a rule.

Greg, Case 75 is an authoritative interpretation of the rules and Case 75 describes a corridor. 

Case 75 “That space was a direct corridor from S1 to a position close to and alongside the mark on the required side.”

I have read 75 and the relevant text is:

So that says the space to sail to the mark was a corridor to a position close to the mark. They describe that to say that a boat outside that corridor is not in the space needed to sail to the mark.

However it is a logical fallacy to invert that. Just because a boat is inside that corridor does not mean she is sailing to the mark.

If Red became becalmed in the zone and spun through 180 degrees before sailing away from the mark. Clearly Red if not sailing to the mark and Blue had no obligation to let Red sail that course, even though Red is in the corridor.

Course matters. Even the case says so:

In short, being inside the corridor is necessary but not sufficient to indicate you are sailing to the mark.

Cheers 

Greg, with all respect, I believe it is you who is flipping it around. 

Why do we care about this corridor?  It’s because a boat that is entitled to room or mark-room has access to exoneration through both 43.1(b) and (c). 

We ask, ‘Was the boat entitled to room sailing within the room she was entitled to?’  If “yes” then she is exonerated under those rules based on the parameters they describe. 

When we are talking about mark-room, we look to Case 75 to help inform us to determine what that room looks like. 

This OP scenario fits Case 75.  Red’s mark-room is that corridor. A PC would look where Red was when she broke a rule covered by 43.1 (b) or (c) and if Red was in that corridor, they should find she was sailing within the MR she was entitled to and thus exonerate her for breaking those rules if the other conditions for rule 43 are met. 

Blue did not act to provide Red the room she was entitled to and contact happened in that room. Blue did not provide Red the room. 

Had Blue altered course immediately as he entered the zone, Blue could have given Red her room. 

Neither room nor space can be defined simply by position on the water.

When necessary the rules are happy to use a position (e.g. the zone, 2 boats legs to leeward, clear astern, etc).

Yet the rules don't use position nor corridors nor zones to define room. Room is defined by the
 space needed to do something. E.g to sail somewhere. It's not just the right to be somewhere.

If the rules wanted to exonerate a boat for being in a corridor, then they would just describe the corridor. They don't, because sailing in room is more complex than just where the boat is.

At least that's how I interpret it. But I'm just a club judge with a bias against boats that needlessly break 14 on the basis they might get exonerated.  If given the opportunity, I'd rule against Red, but would be really interested if it ever went to appeal... as there is a good chance that I'm wrong.

The diagram shows that at position 2, Red breaks RRS 11 and RS 14, when she changed her course toward and made contact with Blue. Red is a W keep clear boat. Blue cannot change course in both directions without immediately making contact. 
Blue's obligation is to give Red room at the Mark to sail the course. The diagram does not show any issues at the Mark or how Blue failed to give Red Mark Room. 

The definition of mark room includes room to sail to the mark when her proper course is to sail close to it. The original post says blue was headed on a course to make a close rounding so was denying red mark room.

RRS 18.2b says If boats are overlapped when the first of them reaches the zone, the outside boat at that moment shall thereafter give the inside boat mark-room. If a boat is clear ahead when she reaches the zone, the boat clear astern at that moment shall thereafter give her mark-room. 

So blue must give red mark room from the moment the first boat reaches the zone. She cannot wait a couple of boat lengths before giving that markroom.

This hasn't always been the case, I think room to sail to the mark was introduced in the 2013 rules.

RRS 18 does not negate Part 2 Section A & B rules. W is the keep clear boat and may not cause contact if possible.
If the Red deems that she was not given Mark Room, she needs to protest. She sailed into Blue 2 BTl from the mark and caused possible damage.  
Nowhere in the rules is that activity allowed. In the hearing, she may prevail on rule 18, but will be DSQed under rules 11 & 14.  
Just because a boat is sailing a course close to the mark, doesn't mean she was not able to give Red room to sail the course. You need facts to support that decision. 

Kim, no damage reported in the OP, just entanglement and loss of BL’s.  Entanglement alone is not “damage”.  Also the OP does not site the RRS term “disabled”.  The description of the “loss of 10-15 BLs” certainly sounds like both boats finished (but should be confirmed). 

Assuming that the above is true, Red is sailing “to the mark” on a course to leave it on the the proper side.  Are you saying that it is your opinion that Red is sailing outside the room she is entitled to?

If so, that’s one thing and I’m interested to understand your thinking on that. 

If not, then how isn’t Red exonerated under 43.1(b) for breaking rule 11 and 43.1(c) for breaking rule 14 (again assuming “no damage” based on facts in OP). 

Angelo,
Further to my post at the beginning of this topic, I think red broke 11 and 14, and Blue broke 14 and 18.2b, and because of Blue's infraction, Red is exonerated under 43.1b. The two RC boats became entangled and lost places. As a result, under Appendix E, Radio Sailing, definition of "disabled", a boat is disabled while she is unable to continue in the heat, and as applied in RC racing, Appendix E 6.6 supplements RRS 62.1 with (f) which gives a disabled boat the right to request redress.

Note: if Red was unable to finish as a result of being disabled, Blue must retire. E.4.3.c

Tim, it appears to me by the OP that the boats finished, thus “continued in the heat”.  The entanglement kicks-in a changed rule 41(b), which is different from “disabled”. 

Angelo, that's an interesting view. I originally had the same interpretation when first racing in DF65's and IOM's in 2020. The RC definition, says a boat is disabled WHILE (i.e. during the time) she is unable to continue in the heat. If that "WHILE" continues to the point that she can't finish, i.e. she retires, then not only can she request redress, but the boat that caused her to retire, must retire too. This is the way the appendix E "disabled" has been interpreted and applied by an international judge and international umpire who sails in a local DF65, and IOM fleet. He's also been serving as judge at IOM World Championships. The interpretation of "while" is key.

Appendix E 6.6 modifies the 62.1 Redress by adding "62.1(f) becoming disabled because of the action of a boat that was breaking a rule of part 2 or of a vessel that was not racing that was required to keep clear."

Tim, thank you for that correction.

That said, as is implied by your previous posts, rule 43 isn’t modified to include “disabled”. 

This is interesting…

We have the RC rule which says a boat’s appropriate penalty is to retire if she breaks a rule of part 2 and caused another boat to be disabled and retire, but the unchanged rule 43 only uses “damage”.

I guess the assumption is that if a boat is disabled and forced to retire, there must be damage.

PS

A simple rule change adding the language from RC 44.1(c) to a modified 43.1(c) would close the loop.

Append 43.1(c) adding to damage or injury … “caused another boat to become disabled and retire”

Tim, I agree the the interpretation of "while" being "during the time".
Angelo, the criteria of a boat being able to finish would mean the word "while" being replaced by "if". 

The diagram clearly shows that, between positions 1 and 2, the course Blue is steering does not give Red room to round the mark on the required side.  The facts given state  "Blue is headed on a course to make a close rounding", which implies that Red, being to windward and inside, will not have room to round the mark.  In order for Red to round the mark, she will need to alter course to leeward.  From the moment she enters the zone,  Blue is required to give mark room,  which includes, not only room to round the mark, but also room for Red to fulfill her R11 obligation to keep clear of Blue.   Could Red keep-clear of Blue when she altered course at position 2?   As there was contact, the answer is no.  

Murray, the problem i have with your interpretation is that Red was not sailing to the mark, but was sailing to a point wide of the mark. If she had been sailing to the mark, then she would have closed slowly with Blue, who would then have had time to alter course and give Red mark room.

I find it very difficult to accept an interpretation of the rules that allows Red to needlessly hit Blue with impunity and be rewarded with a favourable ruling of 18.

If Red had not turned down so soon and contact occurred near to the mark, then i agree that Blue was at fault and broke 18. But contact was 3BL from the mark and Red was not sailing to it.

Greg W, at #1, blue immediately owed mark room. Also at that moment, the diagram shows a gap which I think is sufficient to take immediate action which blue didn't do. In fact from the diagram, blue made no effort. You are not considering the fact that BOTH boats broke 14, as both could have avoided it at the outset, however at #1, blue was the burdened boat to give room and as there was no move to do so, on the balance of probabilities, blue breaks 18 and qualifies red for exoneration.  I think we all understand room and opportunity, but in RC racing the scale and context of that needs further consideration.

RC boats can turn instantly; they can tack and gybe in under 2 seconds , which in RC racing causes other issues in "room and opportunity" situations for keep clear boats . The skipper that needs to respond can often take longer to think about what's happening and applicable obligations, than move a joystick. Although you aren't obligated to anticipate another boat's actions, the reality is that we all do, and actually have to, particularly when approaching a zone with upcoming, rapid changes in rights and obligations.  You can oversteer easily due to wakes and small waves, and by simply not having enough dampening on a transmitter rudder joystick. Adjustments in sail trim and rudder joysticks are down to millimetres meaning that oversteering/understeering is common. Add to that the distance the sailor is from the action, seeing exact courses and distances, makes precise helming difficult, and recall of exact positioning difficult. Having raced big boats for most of my life, when I started racing these little things, (as do many accomplished sailors and designers e,g. Ken Reid, Bruce Farr, Ron Holland, Kevin Dibley, to name a few), it was shocking how instantly you became a rank novice in boat handling despite years of racing and rules knowledge.

Context of racing these or any boats, is key. Racing RC is often less about pushing your rights to absolute limits, but more about making sure you have extra room, give extra room, take wider lines at turning marks (because other boats block your view, and often you can't see how far or close you are to a mark or crossing situation). Contact is common when you try to push the limits of rights. Contact without damage is common, but contact and entanglement is quite common in starts and roundings. When a keep clear boat or give room boat causes another to get tangled, you can often write off your race, or ruin a position in a race from which you can't recover. You'll notice in Appendix E an emphasis in rules to fairly compensate the fouled boat e.g. the additions to redress eligibility, and extra penalty turns that the boat causing the foul, may be required to do until any advantage gained, is offset.

All the above in racing RC boats needs to be considered in ruling on what was possible, what could have been done, what limitations there might be in responding etc.. In this case, no matter how much one can debate the corridor, what we see in the diagram, is perhaps a momentary oversteer by red for which it broke 14, zero response from blue to an immediate obligation on blue which compounded the contact, hence breaking 14 too, and breaking 18, culminating in getting tangled. That's why red gets exonerated. Cruel, when they both broke rules, but fair.

I think if this were about big boats, blue may not have been so insistent on her course to her close rounding.

Tim, i totally accept that my big(ger) boat bias might not be appropriate for RC boats.  However, it is interesting to see how the rules play out for both big and small boats.

I have considered that Blue was also obligated by 14, but with Red tight on her quarter her ability to turn down was limited. On big(ger) boats I'd consider if Red had already broken 11 before the zone.

If RC boats aren't racing unless they're rubbing, then perhaps the oversteer by Red is acceptable and it's ok the protest goes her way. But for big boats, my bias would be to find an interpretation that discouraged Red's actions.

I do find it interesting that the RC interpretation is forgiving to Red (the keep clear boat) for oversteering and not heading exactly to the mark, yet exacting on Blue (the ROW boat) in expecting her to be precise with her heading when still 3BLs from the mark.  

I don't think big or small boats shouldn't be bumping 3BLs from the mark. So i guess neither boat can complain if they are DSQ'd and the other one should walk away thinking it was a close call that could have gone the other way.

Cheers

Greg,
It appears that where you and I fundamentally depart is at #1. As drawn, and after sailing three RC classes, each with slightly different swing-room needs, (DF65, IOM, Soling) I believe that blue had room to diverge from her course immediately and her course was clearly biased towards her tight rounding and not the boat with nark room rights. Once inside the zone, the windward/leeward, or even a port/starboard positioning is not relevant. What is, is blue giving room, immediately, making a reasonable effort to avoid contact, not a boat length later or at sometime when blue feels like it, but at the 4 BL zone.

RC racing can be at a highly competitive level. They may be small boats, but aren't toys, they are tuned, great attention is paid to weight, sail shape and trim, and similarly, sailing by the rules isn't flippant. Playing bumper boats isn't excused and there's an immediate protest procedure that is actively used. All I said was, the conditions that affect a skipper's precision in boat handling and seeing the action accurately, is markedly different compared to sitting at the helm of a dinghy or a keel boat. As in many one design classes, competition is tight and close action is a fact of life. Due to the reality of being remote from the boat, RC skippers need to take extra consideration of the room and opportunity. That doesn't always happen but it doesn't mean that contact is condoned or excused. The rules aren't forgiving to red. As I said, red breaks 14, but blue made no effort either at #1, 4 BL from the mark when obligated to Red's needs for mark room.

You should try some RC racing. There's lots of it across Australia. You will find it interesting, different, and that experience will aid in explaining the nuances in Appendix E, the RC case book, and what I've tried to describe.

The first response by Greg Wilking is:
Blue owes Red mark room, but mark room does not entitled Red to push Blue down. There was still plenty of time for Blue to give Red room and no indication that she would not have done so.
Red DSQ for breaking 11 as Windward boat she did not keep clear.
The Fact Found is: Red, the keep clear boat failed to do so.

There is no FF that says Blue failed to give mark room to Red.
Rules are designed to keep boats apart. When a boat that is a keep clear boat changes her course and makes contact with RoW boat, she breaks a rule. Red had room to keep clear and failed to do so. The contact includes the contact between the rigs. The PC can sort out the RC definitions about entanglement, etc. later. 
Any discussion about Red's mark room etc. is meaningless in the absence of FF that finds: Blue failed to give mark room to Red.
This applies to all racing boats.
Red's option was to keep clear and file a protest if she was not given mark room. 
Case 75 -When rule 18 applies, the rules of Sections A and B apply as well.
Appeal 20-Mark-room is not defined to allow an inside boat without right of way to sail to a
mark in a tactically desirable manner.

Case 118 states "In the definition Mark-Room, the phrase “room to sail to the mark” means space to sail promptly in a seamanlike way to a position close to, and on the required side of, the mark."
Case 75  tells us that space is a "direct corridor from S1 to a position close to and alongside the mark on the required side". 

Yes, Red infringed rules 11 and 14 while inside the zone.  Was Red entitled to mark-room?  Yes.  Did Red sail outside the "direct corridor" from position 1 to a position close to the mark? No
Since Red did not sail outside of the room she was entitled to, then rule 43.1(b) exonerates her for her breach of rule 11, and 43.1(c) exonerates her for her breach of rule 14.

Kim stated " Blue's obligation is to give Red room at the Mark to sail the course. The diagram does not show any issues at the Mark or how Blue failed to give Red Mark Room.  "
However, case 118 and the diagram clearly demonstrate that Red did not have space to sail promptly to the mark. At position 2, Blue is clearly inside that space. 

Blue breaks rule 18.2(b). 
 

Murray,

The rule is not written in terms of a corridor. Case 75 uses the concept of a corridor to illustrate that a boat that is outside of a corridor is not sailing to the mark. But the inverse in not true, as being the in the corridor is necessary but not sufficient to sail to the mark. Just because Red is in the corridor does not mean Red is sailing to the mark.

Your diagram shows that at position 1, Red was heading directly down the middle of the corridor and thus could have continued in a straight line and arrived very close to the mark on the correct side.  Moreover, the overlap with Blue was only small, so there are many ways that Blue could have given Red room: she could have sailed past the mark a little and turned late with her stern swinging away from Red;  she might have been sailing faster than Red and if she broke the overlap she could have rounded the mark normally without impeding Red or failing to give Red mark-room; or she could have been slower and sailed wide to give Red room.

But Red didn't sail straight, she turned down so that her course, as indicated by the dotted line, was leaving the corridor.  If she had continued and Blue was not there, then she would have left the corridor and thus is not sailing to the mark.

This has been a healthy debate with good points being made on both sides.  I believe it comes down to these arguments.:

1.  Blue is required to give mark-room, which is: “room to sail to the mark” meaning space to sail promptly in a seamanlike way to a position close to, and on the required side of, the mark.".  There is no indication that at 3BL, Blue could not adjust course and so provide mark-room in a seamanlike way.  Red break R11 and R14.
2.  Case 75  tells us that space is a "direct corridor from S1 to a position close to and alongside the mark on the required side". Blue does not provide that direct corridor so Blue breaks R18.

Now these are RC boats, and while the OP does not state it, this incident occurred about 50m from the skippers.  At the 4BL limit it was difficult to determine whether the boats had entered the zone yet, and impossible to tell if there was an overlap.  Red did not hail "Buoy room".  Blue believed there was plenty of time and space to provide Red with mark-room.

Now John Ball has kindly advised in an adjacent thread, see note below.  

"Also as this is RC, there is a very good section in the World Sailing Call Book for Radio Sailing, titled General Principles  that has comments that relate to room and seamanlike. Here is the section.

1 Limitation on Interpretations
In radio sailing the boat and the competitor controlling her are usually separated by
some, possibly significant, distance. The competitor may not be well placed to view
any incident and to rapidly analyse the relative speed, angle and distance between the
boats. Therefore, interpretations of the rules should be appropriate to the conditions
and should take account of these limitations.
2 Definition: Keeping Clear
A boat is keeping clear if a right-of-way boat can sail her course with no need to take
avoiding action. In accordance with WS Case 50, a right-of-way boat needs to take
avoiding action when she has a genuine and reasonable apprehension of a collision.
If, in such circumstances, she does not take avoiding action and there is contact, the
right-of-way boat will break rule 14.
3 Definition: Room, meaning of 'manoeuvring promptly'
When the term room, as defined in the Racing Rules of Sailing, is used, manoeuvring
promptly includes the time needed by the competitor controlling the boat to analyse
the situation and react accordingly. In radio sailing, this time may be longer than the
time needed to carry out the manoeuvre itself.
4 Definition: Room, meaning of 'in a seamanlike way'
WS Case 21 states that 'extraordinary' and 'abnormal' manoeuvres are unseamanlike.
Some actions that are abnormal in larger boats may be considered normal, and
therefore seamanlike, in radio sailing. However, any manoeuvre that puts a boat at
risk of damage is unseamanlike. It is also unseamanlike to hit a mark, a pontoon, a
bank or a patrol boat"

Considering this I would argue that 
1)  The distance from the competitors to the incident may be a factor in the timing of responses
2)  Red was sailing a course with the ability to pass the mark on the correct side in a seamanlike way, and at 3BL did not need to take avoiding action.  So Blue, at that time, was providing adequate ROW.
3) RC boats can easily manoeuvre promptly within a 3BL buffer to the mark
4) For Blue to adjust at 2BL and still allow plenty of room for Red would not be considered 'extraordinary' or 'abnormal', and so such a response would be seamanlike.

I therefore question the relevance of the Case 75 "direct corridor" requirement to RC boats in this scenario.

The previous diagram was to show that Red was sailing within the room she was entitled to.  In fact, she would be entitled to more room than that which has her scraping her gunwhales down the side of the mark.
At the point when Blue reaches the zone, Red is entitled to  " space to sail promptly in a seamanlike way to a position close to, and on the required side of, the mark.".  She is denied this space when Blue fails to alter course.
To keep clear of Blue, Red would need to alter course from the one she is heading at position 1 to one that is parallel with Blue, and that would mean she would not be sailing to a position close to and on the required side of the mark, but on a course to hit the mark.  From the 4BL from the mark, any delay in Blue altering course is not allowing Red to sail promptly to the mark.

OK, here we go again.
Can anyone show me a rule that allows a Keep Clear boat to willfully make contact with RoW boat?
Sections A and B always apply between boats. Look up the Case listed above.
Red has to keep clear. Rule 11 does not go away at 4 BLT. If she is not given the room to sail the course, she may possibly sail to the wrong side of the mark in order to keep clear, her remedy is to protest. Not to hit another boat!
I am still looking for the FF that says that Blu failed to give Red mark room. 
I will be perfectly happy to toss out Blue when the FF say that Red, while at the mark, did not have enough room to sail the course. Red has to execute a seamanlike rounding. Mark-room is not defined to allow an inside boat without right of way to sail to a mark in a tactically desirable manner. She must sail close in, .....out. 
Cases talk about Sections A & B and rule 31 when it comes to mark room. 

Kim, Rule 11 requires Red to keep clear of Blue and rule 14 requires boats to avoid contact if reasonably possible..  I think everyone on this forum is in agreement that Red infringed both these rules.  No question about that.
Regardless of the reason, whether wilful, or an error, Red broke two rules.  However she may will be exonerated for those infringements if as long as she is sailing within the mark-room she is entitled to (rule 43).
I think the diagrams above illustrate quite clearly that while Blue maintains her course, Red is unable to sail a course  that will allow her to pass close to the mark on the required side and that Red is sailing within the room she is entitled to, From the moment Blue reaches the zone, Blue is required to give Red room to promptly sail to the mark.  The key is promptly, not some time later when it best suits Blue.

Here are the facts from the OP's original post, supported by the diagram with my comments added in parenthesis.
Blue is headed on a course to make a close rounding  {If Blue rounds close, there will be no room for Red to do so.  Therefore she will have to alter course if Red becomes entitled to mark-room}
At the 4BL zone Red has a slight overlap. {At this moment, Red is entitled to mark-room}
At 3BL, Blue maintains course.  {As shown above, by maintaining her course, Blue is denying Red the ability to sail to the required side of the mark. By definition, that is denying Red mark-room}

Murray re: “However she may be exonerated for those infringements if she is sailing within the mark-room she is entitled to (rule 43).”

Remember, each of rule 43’s exonerations in (a), (b) and (c) use the word “is”, not “may be”. [emphasis added below]

If the boat meets the conditions described in each of 43.1(a)/(b)/(c) .. 

So we all agree 

What we disagree on is if Red is sailing within the mark-room she is entitled to?  This disagreement is well illustrated by the image from Murray:

There is some noise on top of all this due to the fact that they are RC boats and exact heading is hard to determine from the shore.  However, I don't think that matters as regardless of doubt the protest committee has to find facts and the diagram from the OP represents the agreed facts found.   So even if it doesn't accurately represent reality, the diagram is the virtual reality on which the rules need to be applied and a decision made.

Team-Red say that Red is in the corridor to the mark so she is sailing to the mark and thus is in the mark-room to which she is entitled.   They say that case 75 supports them by describing the concept of a corridor. [Can somebody from team-red confirm I've captured this OK?]

Team-Blue say that Red's course is away from the mark so she is not sailing to the mark and thus not sailing in the mark-room to which she is entitled.  They think that case 75 does not apply as it is about the negative - i.e. a boat outside of the corridor is not sailing to the mark.   Team-Blue point out that a boat could be in the corridor, yet sailing 180 degrees away frome the mark, so being in the corridor is not sufficient to indicate a boat is sailing to the mark.

I think this really should be the subject of another case to clarify this point.  I'm not sure there is anything else that team-red or team-blue can say to convince the other team (yes I know I shouldn't call them teams - we are all impartial here).

cheers

This certainly been an interesting discussion. 
I am all in favor to submit it to the WS and USSailing as a question.
WS may do Q & A response; USSA may put it out as a Question in their Appeal book.
WS needs an IJ to submit. For USSA, the question must come from a club that is a member of USSA. There is a small fee at USSA. I think $25.00.

This topic raised in Australia describes a Radio Sailing incident. Appendix E for Radio Sailing was developed because of the different context of sailing by RRS, while operating a boat remotely. Appendix E modifies some of the core racing rules to cater to this different context e.g. different procedures for hailing for room, lodging a protest, requesting redress, redefining certain terms, size of the zone, penalty turns, etc... I've attached two images, one giving some background on why Appendix E was developed and who was involved, and the second image, from the Radio Sailing Call Book, with a WS suggestion on how to make contact to review rules, issues and requests to consider changes for the nuances in Radio Sailing presented when applying the standard RRS.

In this thread, the context of RC sailing may have been considered as noise that overlaid how to interpret this incident. Perhaps this incident highlights the difficulty in Radio Sailing, in ascertaining with greater certainty the relative positions of boats, ensuring from a remote position that adequate room is given (definition of room, mark room and keeping clear and RRS18 to 20), and the the challenge that sub 2-second boat manoeuvres pose on the rules calling for room and opportunity (e.g. RRS 15 and 16).

E.g. 1) since the zone has been enlarged in RC sailing, should outside RC boats be required to give a defined distance for "room" that is more easily seen from a distance, for example: a defined width of corridor measured in 2 boat beams? 2) when boats can tack and gybe in under 2 seconds, a burdened boat's skipper needs time to assess the situation and may need twice the time to assess, and then comply with the burden. Should under RC racing, there be a time frame in seconds that define adequate opportunity e.g. 4 seconds and also using the 2 boat beams as adequate "room". 

These enhancements to the RRS may reduce the incidences of contact, entanglement etc... and make it easier to see situations develop and apply rules in tactical situations with less ambiguity, predominantly caused by distance and lack of clear views.

If the interpretations in this Radio Sailing incident warrant submission for clarification, perhaps it best be done through those that developed Appendix E and the Radio Sailing Call Book.

Tim,

My description of RC issues as "noise" was not meant to be a perjorative.   I think RC racing is as deserving of serious consideration as any other style of sail boat racing.

Appendix E does refine how protests are heard with RC considerations, but that is mostly with regards to witnesses and evidence. Once the facts are found, I believe any RC protest progresses on the same basis as for non-RC boats. In this case, I think we have a very well agreed set of facts.  Just differing interpretations of how the rules relate to them.

regards

P.S. I don't think that sailing big(ger) boats gives any particular clarity for witnesses and evidence.  Angles, distances, velocities and headings can be just as hard to judge when standing within the lifelines as they are from standing at some distance.  Layer on imperfect recall and wishful thinking and the process of finding facts is always difficult.   However, once facts are found (even if they don't match reality), it should be possible to apply the rules with clarity and precision.  This is an interesting case because whilst the facts are very much agreed, there a different interpretations of the rules.

Greg, I don't disagree with the process of holding hearings or think that the process is any different for any class of boat. I do however think that the conduct of RC Sailing has nuances that could be further catered to in more tailored rules. It would be easier to avoid situations, contact and entanglements like this thread. Most RC incidents result in immediate verbal protests and resolution, some immediate and hopefully short,  dockside debate, and don't often go to a hearing. If they did, describing the events, fact finding, and applying a clear rule interpretation as a result of more tailored rules, better and fairer decisions could be made. e.g. at #1, your interpretation of the gap between Blue and Red leads you to find a fact that Blue didn't have room to give room, so leads you down a different path of consequences. When I look that gap, and imagine they are any number of popular RC boats, and knowing how fast they turn and swing radius, I find that Blue had room to alter her course as drawn direct to the mark, to one leaving a "corridor". If in RC sailing the room, and opportunity definitions were better defined, we would be less likely to see two different consequences of that gap at #1. Anyway, it's been a healthy debate.

Tim, I’d like to thank you for sharing your depth of knowledge regarding RC rules and experience both racing and officiating in their events (and now a history lesson to boot) with the forum. 

I certainly have gained a better understanding of some the particulars from what you have shared with us (and from the occasional slap across knuckles with the ruler :-D). - Ang

One of the things particular to RC sailing that Greg and others may have overlooked, in considering if Red is sailing outside her room entitlement, is that on a downwind leg, the room required may extend beyond one and a half boat widths.  Consider, for example, a K2 IOM which has a beam of approximately 7 inches.  The A rig jib boom end is approximately 12" from the pivot point, meaning the end of the jib boom, when running wing and wing, will be approximately 1.7 boat widths from the centreline.  Given the wind direction in the OP's diagram, it is highly likely that Red was sailing wing and wing with the jib boom to port.  The red line in the diagram below indicates the end of the boom and counterweight.  Considering this, I would say that Red's heading at position 2 is within that required to ensure her jib boom does not touch the mark

Murray, 

Perhaps....  further questioning of the boats about that before finding facts would have helped.

But with the facts found, we know that that Blue is on course to make a close rounding, and I would expect Blue to have the same sail plan up as Red, so Red is still trying to take more room at the mark then the FF say are sufficient for Blue.
If both boats were heading for the same close rounding, then I would expect contact to be much nearer to the mark than at 3BL.  Instead, Red changes course and hits Blue way before the mark, when the preferred action would be to avoid contact, protests and/or to hit the mark instead.  My interpretation still is that she has sailing to make contact with Blue, which is not sailing to the mark.

Also if these boats are in a wide configuration, then I refer back to my thoughts many posts ago that I think Red has started this sequence too close to Blue.  If she was inside of Blues jib boom when she was overlapped when outside the zone, then I doubt she was keeping clear at that point.   Red cannot demand 1.5 boat widths of room at the mark, yet be happy to maintain an overlap to windward of about half a boat width!   The closeness of that overlap was either too close or establishes what distance Red thought was appropriate in the conditions.

So I remain convinced that Red should be DSQ'd.... but maybe a little less so.

cheers

I would like to thank everyone for contributing to this thread.  It has been extremely informative.  Whilst I have many decades of experience in racing sailing, I am very new to RC boats, and this discussion has highlighted some nuances that are worthy of consideration when applying the rules.  Again, thanks all.

Greg,

Absolutely agree.  However, we a are limited by the information at hand.

Are you suggesting that Red must be overlapped more than one and a half  boat widths from Blue's aft quarter in order to be deemed keeping clear? 
Or perhaps Blue"s jib is attached aft of her rudder?

Murray, If Red is saying that she needs 1.5 boat widths to round a mark, then she should be giving Blue at least that so she can sail her course and change direction. Remember that marks don't have booms but both boats do, and that booms can change sides as a boat changes direction.

If i was sailing my boat and had the bow of a windward boat overlap me within the width of my Spinnaker pole, then i would definitely feel they were not keeping clear. Perhaps that's my big(ger) boat bias.

My point is, that if these boats need a lot of width to get around a mark, then why were they so close together in the first place?

If at #1, Blue had turned down significantly, then i think there would have been contact, specially if Blue slowed down in there process.

I doubt Red was keeping clear before the zone and do not believe she was sailing to the mark at the point of contact.

Greg,

Blue has no entitlement to mark room from Red.  At position 1, Red keeps clear of Blue if :
a) Blue can sail her course  without having to take avoiding action 
b) Blue can change course in both directions without immediately making contact 

As seen by the diagram, both conditions are true, so, at position 1, Red is keeping clear.  
Also, at position 1, if Red were to maintain that heading, her jib boom would, in all probability contact the mark.  She needs more room that that which Blue is giving her at position 2 in order to sail her course to round the mark without contacting it and, at the same time, remain keeping clear of Blue.  

And remember that, as Red changes course to round the mark, her jib boom will change side from port to starboard and that will require more room to have been given by Blue.

I think Red was keeping clear at position 1, was not keeping clear at position 2 and Blue did not promptly act to give Red room to sail to the mark and round it.

Murray,

I think you are assuming equal velocity, so that as blue changes direction the overlap is broken.  This is probably not the case as Red is behind Blue taking her wind and a few moments later Red changes course and immediately hits Blue on the quarter not the stern. 

Besides, if Blue did turn as you indicate at #1, her stern would be extremely close to the faster bow of Red and a collision from astern would be very likely.  We'd need to know a little bit more about relative velocities and for how long the overlap had been established to know if such contact would meet the "immediate contact" requirement.

My point remains that Red's overlap was establish very close to Blue, so much so that Blue's ability to quickly change course is likely to have been constrained. thus a significant turn down by Blue between #1 and #2 would have risked a collision.  Somewhere between #1 and #2 Red turns down and her bow does not pass astern of Blue, so at the same point a similar turn by Blue probably would not have resulted in her stern clearing the bow of Red.

So I still maintain that Blue was unable to do a big turn down because of the close overlap from Red, but that if she had does a slow turn down from #2, then Red would have had room to sail to the mark.   

Greig Ebeling,
Please can you provide more info; what class of boat is involved, where and how were they entangled (an additional diagram would be useful), what were the conditions in terms of wind speed, gusts, wave heights, current speed and direction, seconds to the mark from #1 where Blue crosses the zone, seconds to the mark from where Red is drawn at #, and the gsp at #1 between red's bow,  and blue's stern. Were there other boats in the vicinity?

Hi Tim,

These are RC boats (DF65s).  After contact the red boat bow hooked onto the blue boat back stay and spun her 180 degrees to starboard, remaining connected for about 10 seconds.  Conditions:  5 knots, steady, flat water, no current.  The boats were 3BL from the mark, and so a few seconds away from rounding, however in RC boats this is an eternity since they are so maneuverable.

Greig, thanks for the info. Was it the extended jib boom counter weight on a winged out jib that hooked the backstay? Were they using their A+ rigs?  If so, with that wind speed they were probably under 4 seconds from the mark when at the zone?

No, it was not the jib boom that fouled.  There was near zero overlap.  I think the top of Red's rubber bow bumper caught Blue's backstay hook.

Using A-plus rigs, so somewhat underpowered for the conditions.  But, yes, I would say about 4-5 seconds from the mark.  As I said, an eternity for RC boats.

If contact was on the back stay, then it is probably rule 12 rather than rule 11 that is at play. I'm not sure that it changes much.... Although blue turning down may not have avoided the contact as Red was likely faster as she was blocking the wind to Blue.

Red had an overlap, broke that by turning down and then hit Blue from astern as she was faster. I'm not sure Blue could have done anything to avoid Red.

Greig, the class went to the A+ masthead rig because the standard, fractional A rig was definitely underpowered at 5 knots. I'm having difficulty seeing from the original diagram, the sequence of events. Are you saying that the diagram is correct, and that the contact with the Blue's windward port quarter, shoved Blue's stern to starboard, thereby swinging Blue's bow to port and across Red's path (180 degrees?? that would have Blue facing Red?) , in such a way, that Red's plumb bow got stuck on Blue's backstay? Or are you now saying Red shunted into Blue's stern and shoved the stern to starboard? Was there actually an overlap? If no overlap, then Red would be DSQ'd for R12. Here are some pics of the DF65 bow and stern. I'm having difficulty seeing how the bow gets entangled on a backstay if Red has spun Blue 180 degrees.

Tim, 

The contact occurred 30-40m from spectators, so I cannot provide an definitive description of the post contact situation.  Here's my best estimate.  It appeared initially that Red contacted Blues port quarter very close to the stern, and then slid across the stern from port to starboard, catching on the backstay hook.  As this was happening Blue was steering to starboard in attempt to give Red room.  Blue steering to starboard and Red pushing from behind meant that Blue jack knifed to starboard, and turned rapidly 180 degrees to head to wind.  Red followed Blues turn for 90 degrees and then detached.  That's the best description I can provide based on my recollection.  

Greig,

Thanks for the extra detail, even if understandably uncertain.    However, I think there is enough there to say that more PCs would find facts that included a slight overlap.

However, there is new information as well, specifically that at around the time of #2, Blue was steering to starboard in an attempt to give Red room.    This really suggests to me that Red was not keeping clear by her close overlap, as Blue was not able to turn to starboard without making contact.   Blue was giving mark room, but Red was too close and too aggressive.     So I'm still DSQing Red.

 TR Call J1 demonstrates that a boat cannot delay giving mark-room. 

TR Call J1
Rule 18 starts to apply when one of the boats enters the zone. From that moment Y
must sail a course to give B mark-room. By maintaining her course to position 2, Y
breaks rule 18.2(b).
It is not significant whether or not B hails for room.
A boat required to give mark-room is required to do so from the time rule 18 starts to
apply.

By holding course till 1 BL after entering the zone, Blue breaks rule 18.2(b)

In the OP I defined the situation that both parties agreed to the EXACT moment when R18 came into existence and that there CERTAINLY was an overlap.  That was deliberate in order to eek out how a PC would respond based on that  specific criteria.

However this is RC yacht racing.  If this was a real protest then it would be near impossible to know the EXACT moment R18 switches on.  Red might claim that R18 has switched on prior to 1, and Blue deny R18 had switched on until after 2.  Further, it would also be impossible to determine if there was a genuine overlap.  Again, that would be would be a contestable fact.  Yet a serious collision has occurred.  So speculating (as I have) the case with an unrealistic degree of certainty, we can determine a suitable set of  responses to the real situation, as follows:  

As Blue and Red approach the mark; 
1. Blue should be conservative in deciding when she reaches the zone, she should assume an overlap and immediately provide mark room.  
2. Red should not seek mark room by turning toward the mark until she is certain that they are inside the zone and R18 applies.  While not required, it would be wise to hail "mark room #xx!" prior to entering the zone.