Forum: Rule 18 and Room at the Mark
Is the offset a separate mark for RRS 18 ?
Joe Erwin
Nationality: United States
Certifications:
- Club Judge
0
Facts: A is clear ahead as it enters the zone of a windward mark to be left to port. B is right behind A. A rounds the windward mark clear ahead but B establishes an overlap to leeward of A on the short leg to the offset mark. Boats are of the same class in the same race.
Questions: Is A required to give B room? Is the offset a separate mark from the windward mark ? Or does the status for the windward mark control what happens at the offset ? Does it make a difference if the offset is more or less than 3 boat lengths from the windward mark?
This scenario arose in a recent race but was not the subject of a protest.
Questions: Is A required to give B room? Is the offset a separate mark from the windward mark ? Or does the status for the windward mark control what happens at the offset ? Does it make a difference if the offset is more or less than 3 boat lengths from the windward mark?
This scenario arose in a recent race but was not the subject of a protest.
Comments
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Usually the offset windward mark is designated as a separate mark of the course and has the letter “A” appended to it (example “1A”) and is listed in order with the other marks of the course. Thus, 1A is a mark of the course and as such has its own zone.
To your 2nd question, being that each mark has its own zone, MR is calculated separately for each mark, determining overlaps, etc when the first of them reach the each mark’s zone independently. . Therefore, “when” MR is calculated for the offset will depend whether or not the distance is greater/less than 3BL. If less, Boat B would need to establish inside overlap before Boat A reaches the windward mark (assuming they are both basically on the port tack layline).
All that said, the offset must be properly described in the NOR/SI as a mark of the course.
I would like to see a SI in which the offset mark is not a mark of the course!
Marks don't blink on and off like traffic lights. An object either is a mark or is not a mark.
What does change is a boat's obligation
course on which she is sailing.
IF the two marks are less then 3 boat lengths apart, your boat is never approaching the zone, rather wouldn't the Rule 18 obligations for the offset just turn on when the first boat of the pair rounds the windward mark on proper course to the offset? The offset mark does not bound the windward leg, therefore under the rules it is not a "mark" until one of the boats is "about to round" on the short offset leg. At the zone, becomes, as they rounded since they were nominally in the zone as soon as the leg started. Zone 1a does not exist for either boat until at least on of them is on that leg:
Of course, the obvious answer is don't set up your course like this....
A horrible SI example.
My point was to say if it’s listed as a mark in order and with a side … it’s a mark. If not, it isn’t.
Overlapping zones could create all sorts of excitements for the sea lawyers (overlap existed for 1 but was broken for 1A and the like), but I tend to think that in practice offset marks close enough to create the sort of excitement where 1 is within the zone of 1A would be so close as to have very little value.
The distance was not reported to me, hence my hedging on if it made a difference. The offset was not specifically called a mark but it was described with the qualifying phrase " . . . if an offset mark is used in conjunction with the windward mark it will be a red sphere." The course illustration, as appropriately referenced in the SIs, shows the offset with the windward mark and an arrow showing the path around the windward mark and the offset.
The illustration by Mr. Townsend reflects the relationship of the boats at the two marks but, again, I am not sure on the distance between marks.
The close but not perfect analogy is when the marks for the leeward gate are set less than six boat lengths apart.
Summaries of scenarios depending on the distance between the marks (from the preceding comments):
1. Offset (O) is within the 3-boat length circle of Windward Mark (WM): Clear ahead boat or inside boat has rights at WM and O.
2. O is more than 3-boat lengths from WM but less than 6-boat lengths so that the zones overlap: RRS 18 turns off for clear ahead or inside boat when it has passed WM, new RRS 18 situation starts when the zone for O is hit (this seems unsatisfactory and unworkable given the normal type of activity when rounding a windward mark).
3. O is more than 6 boat lengths from WM. Two different RRS 18 scenarios with "clearly" determinable zones for each mark.
Thanks for everyone's comments.
This is an interesting observation, except “about to round” might not be the best measurement-point.
Case 126 deals with determining what leg boats are on for the purposes of rule 23.2. In A2 it describes the boat was sailing on the downwind leg, “…from the time she rounded the windward mark” (not “about to round”).
Both def: mark and def: zone are static relative to 1A in that:
Rule 18.1 tells us that, “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.”
I believe your point is that rule 28 tells us that a boat “ ..may leave on either side a mark that doesn’t begin, bound or end the leg she is sailing” and therefore Boat B isn’t “required to leave” M1A to port until she rounds M1. Following that logic, rule 18 would not apply between them in the 1A zone until both boats are on the M1 to M1A leg (since Boat B can leave M1A on either side until she rounds M1), which would be when Boat B rounds M1.
But this comes down to the meaning of “required to leave” in 18.1.
I had a long offline discussion with a highly experienced rules person about this issue stemming from another thread. That person took the position that “required” referred not to their current state, but rather a more over-arching “required to leave” which references back to the course definition (I was taking the other position that “required” was based on an analysis of the “current” required-mark-side-status of the boats). In the end, I deferred to their interpretation (but argued there was some ambiguity there).
So, I believe this person might argue that, based upon the course description, both Boat A and Boat B are “required to leave” M1A to port, regardless if Boat A is on leg 2 and Boat B is still on leg 1 and therefore 18 applies between them when the first of them reach 1A’s zone of 3BL’s.
Angelo Guarino
Do you have in mind that RRS 18.2(b) won't apply with respect to M1A, and that we'll fall back on RRS 18.2(a), so that if inside/outside changes then mark-room will change?
Practically seems pretty unlikely with marks close together, unless in very light and tidal conditions.
Could you expand on the context of that discussion a little? I'm having difficulty grasping what difference it is supposed to make.
I was about to say that 'required side', like 'mark' doesn't blink on and off, then I realised that 'required side' is contextual: the required side of the same mark can, for other than simple W/L, Triangle or Trap courses, change depending on the leg being sailed.
Doesn't that put paid to the 'over-arching' approach?
Consider vertical offsets: in some SI the downwind mark is specified as the offset.
The 7 boat lengths guidance applies to gates so as to ensure that zones don't overlap such that boats going through the gate could be in the zone of both marks at once and have simultaneous and contradictory mark-room obligations/entitlements.
That problem doesn't apply at a windward offset where boats pass around the outside of both marks.
Possibly, as Angelo has raised there may be some obscure problem when the offset is less than 3 boat lengths from the windward mark so that the windward mark is inside the zone of the offset, so at least 4 boat lengths for the offset would be a good guide.
I seem to be seeing a trend to lay quite long offset legs, 100 or 200 m.
Is anyone else seeing this?
Does it seem like a good idea?
Is it particularly applicable to high performance boats?
I’m not an RO, but as a competitor I want 2 things out of an offset
In the J105 (an ~ 10m boat), if we have enough wind we are traveling 7kts between M1 and M1A .. that’s 3 sec’s per BL. So that’s 21 sec’s … that seems long. Take the wind/boat speed down that’s even longer. That’s a diff calc for a small fast skiff.
I’m thinking 4-5 BL should be fine IMO from a competitor’s perspective.
OK … let me give it a try.
As I recall the discussion was kicked-off by considering what happens at a finish mark.
Consider the following together:
So, once a boat’s bow crosses the finish-line, she no longer has to pass/leave either finish-mark on a specific side, but until she clears the line and mark-influence, she is still racing.
Imagine Boat A on a DW finish on starboard gybe in light air. She is working against a strong adverse current as she approaches the pin-end of the line. In the absence of other boats, Boat A would cross the line near the pin and simply head-up and be pushed by the current, clearing to the course-side of the line and past the pin, leaving the pin-mark to port after finishing.
On port gybe is Boat B, overlapped inside Boat A approaching the same pin from outside the line. Boat B is on a trajectory to reach the inside of the pin just after Boat A.
If we take the interpretation that “required to leave” is “
contextual” [situational], as soon as Boat A’s bow crosses the line, the finish-line pin no longer has a required side for her as she can leave it on her port or starboard side as she clears the line and marks. Following that logic, at that moment, Boat A and Boat B would no longer be required to leave the pin-mark on the same side and thus 18 would no longer apply between them.The “
non-contextual” [non-situational] interpretation is based solely on the course requirements which do not change based on the finish-status or leg of a boat. Boat A and Boat B are required to leave the finish-pin to starboard based on the course requirements, which didn’t change once Boat A finished. Therefore, Rule 18 still applies between them and Boat A owes Boat B mark-room at the pin.I had a long offline discussion with a highly experienced rules person about this issue stemming from another thread. That person took the position that “required” referred not to their current state, but rather a more over-arching “required to leave” which references back to the course definition (I was taking the other position that “required” was based on an analysis of the “current” required-mark-side-status of the boats). In the end, I deferred to their interpretation (but argued there was some ambiguity there).
I think that we may be mixing things up:
- a mark is any object the sailing instructions require a boat to leave on a specified side... .(see definition Mark)
- a boat is required to sail the course by passing or rounding each mark of the course for the race on the requires side and in the correct order. (see definition Sail the Course)
- while sailing the course, a boat may leave on either side a mark that does not begin bound or end the leg she is sailing (RRS 28.1)
- RRS 18 applies between boats when they are required to leave a mark on the same side and one of them is in the zone.
Concerning rule 18 at the offset mark:
- Boats sailing towards the windward mark may pass on either side of the offset mark.Therefore, RRS 18 cannot yet apply between them at the offset mark.
- Boats only become required to pass the offset mark when they are at the windward mark, and begin sailing on the leg from the windward leg to the offset leg.
- RRS18 cannot begin to apply at the offset mark until boats begin to be required to leave it on the required side, that is once they are on the offset leg
- . RRS 18 only begins to apply at the offset mark when boats are sailing on the offset leg and one of them is in the zone of the offset mark. one of two boats sailing on the offset leg reaches the zone of the offset mark.
Before boats are at the windward mark and are not sailing on the offset leg, RRS 18 applies at the windward mark.
Once this is understood there should be no confusion due to an overlap between the zone of the windward mark and the zone of the offset mark.
At the finish-line:
The finish mark is a mark because it is an object that the SIs require to leave a specified side. Once it is in the place it is a mark, and remains a mark according to the definition until it is removed.
The finish mark has a required side for boats sailing from the last mark to the finish. Rule 28 applies, as does rule 31.
Once a boat has finished the finish mark no longer has a required side. Rule 28 ceases to apply.
However, while the boat is still racing RRS 31 continues to apply, and the boat must not touch the mark
- . RRS 18 only begins to apply at the offset mark when boats are sailing on the offset leg and one of them is in the zone of the offset mark. one of two boats sailing on the offset leg reaches the zone of the offset mark.”
We were discussing the instance that M1 and M1A are less than 3BL. So based on the above, would that mean that 18 doesn’t apply between them for M1A until the boat behind (Boat B in the OP) starts the offset leg (which is after she rounds M1)? In that case, the first of them (Boat A) would be well within the zone.
At the finish. the issue is how do we preserve MR entitlement for an inside port-gybe boat at the pin who has yet to finish vs a STB-gybe boat who has just finished, is holding course, and has yet to clear the line/marks (STB is still racing thus rule 23.1 does not apply between them)?
Port’s expectation will certainly be that she is entitled to MR at the pin from STB.
As you say, rule 28 no longer applies to STB. Would we apply rule 23.2? .. that port is on a different leg than STB since STB, having finished, is no longer sailing a leg of the course and that STB no longer has a proper course (and thus no proper course defense in 23.2)?
This doesn’t get port MR exactly, but would put the onus on STB to maneuver to get out of the way of port (which would likely look much the same as MR)
There is only an issue when the offset mark is less than 3 hull lengths from the windward mark. Both boats become required to leave the offset mark on the required side when they are on the leg to the offset mark. In which case rule 18 only starts to apply at the offset mark when both boats are already in the zone. I would argue that 18.2(a) applies.
At the finish mark:
The rules of Part 2 apply to a boat that intends, is or has been racing.
A boat that finishes is still racing until she has cleared the line.
The entitlement to mark room continues:
- under 18.2(a) while boats are overlapped
- under 18.2(b) from the time that a boat becomes entitled to mark-room until it has been given.
Case 127 is interesting: A boat clears the finishing line and marks when (...) no finishing mark is influencing her choice of course.
If a boat that has finished is required to give mark-room to a boat inside her at the finishing mark then the finishing mark is still influencing her choice of course, so she is still racing!
"The offset mark
A variation to the above courses consists in adding an extra mark close to the windward mark, usually called ‘offset mark’. This is the term applied to a mark which is set some 50
to 100 metres on the port side of mark 1 (or, for starboard roundings, on its starboard side).
Its purpose is to prevent boats rounding the windward mark from immediately setting off on the run and hoist spinnakers, thereby reducing potential interference with boats still beating to reach the windward mark. Its location in terms of distance and angle from mark 1 are very type of boat specific and the advice of the class association should be sought at an early stage of the planning process."
US Sailing's Race Management Handbook also addresses the offset mark and also mentions talking to the class. As for location:
"In view of the purposes of the offset mark, it should not be far from the weather mark. Generally, all of these goals can be accomplished by placing the offset mark about 6-10 boat lengths from the weather mark. It is critical to place the offset mark above the layline to the weather mark, or it will not accomplish at least one of its purposes."
US Sailing's Basic Race Management Seminar has an overhead picture of a large Etchells fleet at the windward mark. It was taken as a large number of boats were approaching the mark on both laylines, boats rounding the mark, boats on the short reach to the offset, and finally boats that had rounded the offset then under spinnaker. It is easy to see how the offset prevents boats from rounding the windward mark into boats approaching the mark on the port layline. It shows that the offset is placed so boats may not carry their spinnakers, however there is time to set the pole after rounding the windward mark before rounding the offset. A really great photo depecting the utility of an offfset mark. I wish I could share it, but I believe copyright prevents me.
- under 18.2(a) while boats are overlapped
- under 18.2(b) from the time that a boat becomes entitled to mark-room until it has been given.”
Absolutely she is still racing until she clears the line and mark influence. That’s my point really.
On what basis do we continue rule 18 after starboard has finished? She no longer has to leave the pin on the same side as port (as you said before, after finishing 28 no longer applies and starboard may leave the pin to either side after finishing) thus the 1st sentence of 18.1 fails.
PS: That is how these 2 scenarios are similar.
At the offset, MR for M1A can’t apply between Boat A/B until Boat B rounds M1 (until then, 1st sentence of 18.1 fails)
At the finish, MR can’t apply between port/starboard after starboard finishes (after then, 1st sentence of 18.1 fails).
Q: Can a requirement of a rule, once applying between 2 boats, continue to apply between those boats past the point the application requirements of that rule are no longer satisfied?
In the instance of rule 18 at the finish, the question above comes down to this …
So, do we have any instances in the Cases where we stop the application of rule 18.2(b) MR because of the failure of a rule 18.1 application test (“thereafter” does not last past a rule 18.1 failure)?
The answer is “yes” (emphasis added)
PS: If we want to take a “non-situational” interpretation of “required to leave” (as discussed previously) to preserve a finish-mark side requirement after a boat finishes, then we have to look back at the OP example and apply that same standard to mark-room around marks between boats in the zone of a mark where the boats are in different legs of the course.
There are two ways of looking at this:
- under RRS 18.2(b) once a boat becomes entitled to mark room then other boat must thereafter give that mark-room ' The 'thereafter' means that the boat giving mark-room to the entitled boat must do so until the entitled boat no longer needs it. This applies while the boat giving mark- room is still racing, and if she is required to manouevre to give mark room then the mark is still influencing her choice of course.
- TR call E2 is interesting, in that contact between boats that are on opposite tacks may be evidence that the outside overlapped boat was not giving the inside boat room to tack before the inside boat passed head to wind. Naturally this call is not authoritative, but it is illustrative and persuasive. So, if there is contact, or a need for an unseamanlike manouevre after the outside boat hs finished this could be taken as evidence that she was not giving mark-room before finishing.
I showed above how Cases 15, 81 and 95 directly contradict that interpretation, so can you support that position while addressing those specific cases?
What are your thoughts rule 23.2? Once a boat has finished, she is no longer sailing a leg and no longer has a proper course … so a boat that has finished, if reasonably possible, should not interfere with a boat who has not finished.
Case 95 involves a boat required to give mark-room, breaking that obligation and then establishing her own entitlement.
In this case the boat that is entitled to mark-room still needs mark-room to sail to the mark and clear the mark.I do not see why she loses that entitlement just because the other boat has finished but is still racing as her course is still influenced by the mark.
The rules do not say that.