Note: This forum is not affiliated with World Sailing and comments on this forum do not represent an official interpretation of the rules, definitions, cases or regulations. The only official interpretations are those of World Sailing.
Maybe I'm over thinking this, but the Mark Room, RoW, Proper Course, Exoneration thread got me wondering. What happens when proper course is not close to the mark? So take this piece of course with a passing mark (wind is from the top), never mind why. blue has luffed yellow into the zone, so RRS18 switches on, and yellow is entitled to mark room. OK, so far so good. But what is yellow's mark room? She is entitled (b) to round or pass the mark on the required side, and (c) to leave it astern. but not (a) to sail to the mark when her proper course is to sail close to it, because her proper course is not to sail close to it. Can blue continue luffing yellow, and if so how far? Can she take yellow way to starboard of the mark provided she states her intention is to eventually permit yellow to pass the mark on the required side? Could she theoretically take yellow so far that yellow would have to sail upwind to get to the mark? a) is interpreted as 'sail directly to the mark', but if a doesn't apply then what? hypoRRS18.jpg8.84 KB
At some point here, her proper course will be to sail close to the mark. Then she can sail to the mark, on either gybe, and be exonnerated till she has left the mark astern. If there are circumstances where this may not happen, then when 18 applies, on a run one is in the zone, the boat entitles to mark room may sail in a seamanlike manner (see room) to pass the mark. Once they are both out of the zone or the mark room boat leaves the mark behind, the right to mark room ceaces.
I agree with MB here. Shortly after the position in the diagram, Yellow will need to sail close to the mid-leg-mark to be on the rhumb line to the leeward mark. As such, her proper course would be to sail close to it.
However, even before that, Blue owes Yellow room to pass the mark on the required side. That means Blue must immediately start giving Yellow the space to do that; indeed a half boat-length ago.
Proper course is "the course yellow would take ... in the absence of other boats mentioned in the rule"
The definition of Mark-room is both not a rule and does not refer to other boats
Further, while 18 does mention proper course (18.1.(a)(2) & 18.4) it does not in any part of rule 18 that matters to this situation.
Therefore: I think Yellows proper course is what they are being forced to do by blue (up to the zone), and then her course is to sail to the mark (once in the zone with 18) if blue continues for press on rule 11
(what Michael is saying in a different way)
My conclusion:
Mark-room applies to yellow
Blue must give yellow mark-room to get to the mark immediately upon one of them entering the zone.
Other Answers:
Blue could luff yellow all the way to head to wind (of blue) as long as the overlap was established properly (17) and is maintained and neither enters the zone overlapped.
This is typically a losing strategy in fleet racing unless blue needed to push yellow back and could afford a drop or something like that
Chris W re:"The definition of Mark-room is both not a rule and does not refer to other boats"
Definition of mark-room is absolutely a rule.
Def: Rule (a) The rules in this book, including the Definitions, Race Signals, Introduction, preambles and the rules of relevant appendices, but not the Basic Principles or titles;
Jim, as an asym racer (J105) those DW angles don't look nutty to me at all. A 140 TWA DW is best VMG at 6kts TWS and 145 is best VMG 8-10kts. What you are showing is just another day at the office in my world.
As shown, Blue could take Yellow above the mark until they reach the rhumbline extension as drawn from the bottom mark through the passing mark. At that point, Yellow's proper course will be to sail close to the mark and she'll be entitled to room to sail to the mark on its proper side.
If Blue alters course to leeward just slightly at the zone, such that Blue will pass the mark to starboard, she has to provide Yellow room to pass between her and the mark if they remain overlapped as shown.
After Yellow leaves the mark astern, 18 will cease to apply via 18.1(b) and Blue will be free to luff again (all assuming 17 isn't an issue).
Mind you if we are considering a boat that sails hot angles and is gybing more than once down a run then potentially she will almost always have a proper course that takes her close to the mark once she is in the zone!
As we are saying that the Proper Course in the definition is dynamic, as seems reasonable from comments above, then its a rather nebulous concept. I'm now thinking OK, what are the circumstances which the test of proper course/close to the mark comes into play, since once she is in the zone it could be considered she is already close to the mark.
I think your answer is the MR A 3: Blue and Yellow are approaching a mark to be left to starboard. What is the latest time Blue may luff? image.png16.5 KB Answer 1 Rule C2.9 (18.1) begins to apply when any part of the hull of either boat is in the zone. From this moment, if Blue luffs and thereafter has to bear away in order to give Yellow mark-room, then Blue breaks rule C2.9 (18.2(a)(1)). Blue does not break rule 18.2(a)(1), if she is able to luff while giving mark-room. Yellow is required to keep clear under rule 11. However, she is exonerated by rule 43.1(b) if she, while sailing her proper course to round or pass the mark, breaks rule 11 because Blue fails to give her mark-room. Question 2 If Blue has to bear away to give mark-room, when is she required to do so? Answer 2 Blue is required to bear away promptly from the moment the first of the boats is in the zone.
Similar answer in TR A 6. Just the rounding is to Port. Kim
Kim that call has them rounding the mark to starboard. That's a significantly different scenario than a passing mark off the rhumb-line between 2 rounding marks.
Hi there, maybe I'm missing something here. But yes, I agree with Kim. If blue has to give yellow mark room, then it assumes that it is starboard rounding. If it were a port rounding, then yellow must give blue mark room. If this mark is not part of the course for this leg, but rather the bottom mark is the correct mark, then it's not a mark, but an obstruction, rule 19 applies and not 18.
Anthony re: "Hi there, maybe I'm missing something here."
The mark in question is not a "starboard rounding" ... it's a "starboard passing". Please see my comments to David later in this thread. It is a mark of the course.
Jim, Blue's best bet is to fall off and give Yellow room to pass the mark inside her. Not much advantage and higher risk in a protest room if she decides to be too cute.
The OP says that it is not yellow’s proper course to sail close to the middle passing mark. It also says the blue boat has been luffing yellow. Yellow’s proper course presumably then is something from dead downwind to slightly above. I think clearly we are left with yellow’s mark room being as Jim says room:
(b) to to round or pass the mark on the required side, and (c) to leave it astern.
This must be done promptly and in a seamanlike way. I would expect that the prompt way to pass this mark leaving it to starboard would be to bear away onto a best downwind VMG course when first entering the circle, which I assume from the OP is either dead downwind or slightly higher.
After leaving the mark astern, mark room ends, and we go back to the situation that existed before the circle was reached and Blue can resume her luff. Assuming it was allowed before reaching the circle.
A similar issue appears in US130 as below: Presumably the boat with mark room can sail any course that they can justify as “promptly” passing the mark in a seamanlike manner from the position where they gained mark room.
Bob re: "This must be done promptly and in a seamanlike way."
IMO, Blue only has to give Yellow room to pass the mark, while Yellow maneuvers promptly in a seamanlike way ... that can be a different course than passing the mark promptly.
Blue is fine, IMO, if she maneuvers and continues on a trajectory toward the mark into the zone and leaves Yellow room to pass the mark on the proper side, as long as during her maneuvers, she leaves space for Yellow to maneuver promptly in a seamanlike way.
If we agree with Drawing 7/Answer 3 in Case 130 ... that has broader implications I feel (it's a spydie-sense feeling at this point ... so will take some thought to see if they (broader implications) actually exist and then to shake them out the tree).
The answer to the Diagram 7 scenario in US130 surprised me.
I would have thought when P reaches the zone in this situation, since her proper course is not to sail close to the mark, ALL she is entitled to with respect to that mark is the space she NEEDS to pass it on the required side (and then to leave it astern), this space being enough so that she doesn’t have to make an unseamanlike manoeuvre, but not so much space that she can manoeuvre at her leisure - she must act promptly.
As P reaches the zone she does not NEED to continue sailing her proper course (thereby failing to keep clear of S) in order to pass the mark on the required side. She is surely therefore not entitled to room to do this.
She is free to gybe and cross any part of the line, thereby passing the mark on the required side. S has clearly given her room to do this.
So it seems to me that P is not sailing in the room to which she is entitled, and so is not exonerated for breaking rule 10.
I can't help but agree with David H here that there is some false logic involved in D7/A3.
A similar situation is when a leeward-outside boat at a downwind buoy must give a windward-inside boat mark-room. We don't allow that mark-room to include unlimited space, just the space the inside boat NEEDS to round. That phrasing is right there in the definitions.
Add: apologies for seemingly putting words in others mouths. That was not my intention.
Yes, I too am surprised by that US130 scenario. I don't see what rule permits P to pass the finish mark without gybing to keep clear of the starboard boat. On the other hand if she does have to gybe away, it seems as if having mark room doesn't give her anything practical at all, which seems a bit perverse. I think I like the interpretation in the case, I just don't understand it.
Be careful using MR calls here because the definition of mark room is very different to that for fleet racing.
Fleet racers only get proper course if their PC is to sail close to the mark.
Match Racers get proper course to round or pass the mark, and room to pass a finishing mark after finishing.
Fleet Racing Racing Definitions Mark-Room Room for a boat (a) to sail to the mark when her proper course is to sail close to it, (b) to round or pass the mark on the required side, and (c) to leave it astern.
Match Racing Definitions C2.2 The definition Mark-Room is changed to: Mark-Room Room for a boat to sail her proper course to round or pass the mark, and room to pass a finishing mark after finishing.
Niko, I also said nothing about false logic, I simply set out the way I see the rules applying in this scenario. Very happy to be corrected if I’m wrong.
To add to Mark’s comment, the US Appeals book 2025-2028 only goes to appeal 129. Appeal 130 is posted as a separate document on the US Sailing Appeals webpage as per Mark’s link. Presumably it will be added to the main document in due course as 128 and 129 have been.
Thanks Angelo, I see your point and agree if Blue gives Yellow room to sail past the mark on any point on the required side that is giving the required room even if it is just the last space before the mark. So “promptly” in the room definition, does not define the objective of the room which is to pass the mark on the required side.
But can it be concluded that “promptly” in the room definition implies that the least room that needs to be given by Blue, throughout the maneuver, is a straight course for yellow from where she enters the circle to alongside the middle mark on the required side? I.e. blue can’t force yellow to sail a looping course above the rhumb line to the edge of the mark. (Dare I say past the direct corridor to the point alongside the mark?). A looping course would not be sailing promptly to “passing the mark” at any point.
Bob .. what I said prior is just my opinion. There is a gray area here that we've been wrestling with that extends from back in the "room to tack" discussion. We never came to a consensus on that thread. This potential tension between US130 D7/A3 and the other cases/appeals I cited brings that same tension into focus in a different context.
Case 75 is clear that the rules of Part 2/Section A&B apply simultaneously with Rule 18.
Case 118 shows that a ROW boat that owes a KC boat MR can use their ROW to influence the course available to the KC/MR-entitled boat.
US20 is an example where the KC/MR-entitled boat did not respond to the ROW boat's attempt to influence her course, even though the ROW boat that owed MR provided the MR-entitled KC boat space to promptly maneuver in a seamanlike way to sail to and around the mark.
IMO, if one applies the methodology described/implied in US20, Case 75 and Case 118 to US130 D7/A3, the boat on starboard is providing the port, MR-entitled boat ample room to pass the mark on its proper side and to leave it astern ... prior to the starboard boat altering course.
Angelo said: Kim that call has them rounding the mark to starboard. That's a significantly different scenario than a passing mark off the rhumb-line between 2 rounding marks.
Kim: The OP course has the mark also passing to Strb. The principal of R 18 begins to apply when at least one of them is in the zone. The OP make it clear that the mark is a mark of the course and R 18 applies: ..."blue has luffed yellow into the zone, so RRS18 switches on, and yellow is entitled to mark room."
As Angelo said: 'this is every day in the office (for J-105's)', blue is happy to sail this course, off the rhumb-line. The MR and TR calls are good illustration of how the boats are expected to behave when they reach the zone overlapped. The definition change of MR in match or team race has not much to do with the principal in this post. No need to dive in that rabbit hole.
Kim ... the difference I attempted to highlight is that in the Call you referenced, the little arrow that shows the direction the mark is to passed/rounded .. is drawn as a "rounding arrow" (it is drawn curved showing a rounding course).
It's been my experience that in cases/calls where the mark is not a rounding-mark, a straight arrow is used with the text "direction to next mark" (or something to that effect) ... and that a curved arrow is used to indicate a rounding-mark.
The difference being highlighted in this discussion is in the instance where it's a passing-mark and the boats' positions are such that neither boat's proper course would take them close to the mark ... and thus the "sail to the mark" component of mark-room does not apply.
Angelo, The picture is the MR call. Do not get stuck on the arrow. Take it out of the picture and you have a passing situation. All the language of R 18 applies and boats should treat it as such. I am under the impression that the OP is asking: "Can blue continue luffing yellow, and if so how far? Can she take yellow way to starboard of the mark provided she states her intention is to eventually permit yellow to pass the mark on the required side?" The MR and TR calls say that the blue boat cannot sail the way the question is asked from the time the first boat is in the zone. I do not see any Rules that change that. Kim
The MR and TR calls say that the blue boat cannot sail the way the question is asked from the time the first boat is in the zone.
Kim .. the Match Race mark-room includes room to sail her proper course. Fleet rules, mark-room does not include proper course. That combined with it being a rounding-mark, makes it quite different IMO.
In the first diagram if the mark circled is part of the course to be rounded to starboard then to sail the course boats must circle it clockwise before sailing to the bottom mark. A boats "string" must touch each rounding mark. The line drawn from the top to the bottom mark does not sail the course.
Hi Jim, If the circled mark is part of the course then if rounded to port it introduces a dog-leg, if rounded to starboard it has to be circled clockwise. Their is no such thing as a passing mark as part of a course, all marks of a course must have a boat's string touch them when "pulled taut". So if that mark is indicated as a starboard mark on the course board it cannot be "passed".
David K re: "Their is no such thing as a passing mark as part of a course, all marks of a course must have a boat's string touch them when "pulled taut"."
That is not correct.
Please see J2.1(4) and def: sail the course (b)(1)
Appx J2.1(4) [SI's shall include] descriptions of marks, including starting and finishing marks, stating the order in which marks are to be passed and the side on which each is to be left and identifying all rounding marks (see the definition Sail the Course);
Sail the Course A boat sails the course when
(a)she starts; (b)a string representing her track until she finishes, when drawn taut,
(1)passes each mark of the course for the race on the required side and in the correct order (including the starting marks),
(2)touches each mark designated in the sailing instructions to be a rounding mark, and
(3)passes between the marks of a gate from the direction of the course from the previous mark; and then
(c)she finishes. A mark that does not begin, bound or end the leg the boat is sailing does not have a required side.
"Rounding marks" are a subset of marks that the string must both pass and touch, out of the larger set of marks that the string must simply pass on a specified side. We commonly refer to those marks, that have a passing-side but are not designated as rounding marks, finishing/starting-marks or gate-marks, as "passing marks".
"Decision of the Appeals Committee The protest committee’s conclusion that the relocation of the finishing line resulted in changing mark 4 from a rounding mark to a passing mark was incorrect. Whether a mark is a rounding mark or a passing mark (see the definition Sail the Course) is not changed solely because the configuration of the course has changed.
Rule 28.1 requires boats to “sail the course” as that term is defined in the Definitions. The definition Sail the Course (b) states, “A boat sails the course when...a string representing her track until she finishes, when drawn taut, (1) passes each mark of the course for the race on the required side and in the correct order (including the starting marks), [and] (2) touches each mark designated in the sailing instructions to be a rounding mark...”.
The sailing instructions did not designate any marks as rounding marks. When sailing instructions fail to identify any rounding marks, boats are not required to treat any marks as rounding marks. Therefore, the boats that rounded mark 4 to port and the boats that only passed it on their port sides all complied with rule 28.1.”
Thanks for explaining that Angelo, and apologies to Jim for having misunderstood this. I have only sailed in club races where every mark is a rounding mark and the situation I described happens when a mistake is made setting the course. Thanks for educating me Best wishes to all, David
David .. sometimes SI's are written such that the marks are defined/identified and given letter/designations and then the course is decided upon on the water by the RC and displayed with placards on the RC boat. In those instances, it is common for the SI's to state that "all marks designated by placards are to be rounded on their specified side" .. making them all rounding marks.
But even in those instances, it is also common for the same SI's to list a series of channel/shoal/gov't marks and state that for all courses they "shall be passed/left on their channel side". So, depending upon which course the RC chooses, these marks can become passing marks that the string may or may not touch. As US103 points out, just because the string touches a mark, does not make it a rounding mark. The SI's must designate a mark as such.
"Shortening the course" is an important reason to understand the difference between passing and rounding marks too.
With all this discussion of passing and rounding marks, I want to highlight one of the important aspects of rounding marks. Rounding marks are one of the few places that an RC can shorten a course and finish. For instance, looking again at US103, since the SI's did not identify any of the marks as rounding marks, it would have been an error if the RC shortened or changed the course at any of the marks.
This is important as sometimes you can have marks designated as rounding marks that the string touches but does not "wrap" around it. In those instances, depending upon the wind direction, the lay lines may be such that a boat may decide for strategic/tactical reasons to sail a course that does not bring them close to the mark (staying close to shore out of current for instance). Boats that do that run the risk that the RC might finish at that mark.
Therefore even though an advantageous layline may not take you close to the mark, it's a good idea, if there is any chance the race would be shortened, to sail at least close enough to all rounding marks so that you can see if an RC boat is there ready to finish.
32.2 To shorten the course, the race committee shall display flag S with two sounds before the first boat crosses the finishing line. If the course is shortened, the finishing line shall be,
(a) at a rounding mark, between the mark and a staff displaying flag S; (b) a line the course requires boats to cross; or (c) at a gate, between the gate marks.
If there are circumstances where this may not happen, then when 18 applies, on a run one is in the zone, the boat entitles to mark room may sail in a seamanlike manner (see room) to pass the mark.
Once they are both out of the zone or the mark room boat leaves the mark behind, the right to mark room ceaces.
However, even before that, Blue owes Yellow room to pass the mark on the required side. That means Blue must immediately start giving Yellow the space to do that; indeed a half boat-length ago.
Other Answers:
Definition of mark-room is absolutely a rule.
As shown, Blue could take Yellow above the mark until they reach the rhumbline extension as drawn from the bottom mark through the passing mark. At that point, Yellow's proper course will be to sail close to the mark and she'll be entitled to room to sail to the mark on its proper side.
If Blue alters course to leeward just slightly at the zone, such that Blue will pass the mark to starboard, she has to provide Yellow room to pass between her and the mark if they remain overlapped as shown.
After Yellow leaves the mark astern, 18 will cease to apply via 18.1(b) and Blue will be free to luff again (all assuming 17 isn't an issue).
As we are saying that the Proper Course in the definition is dynamic, as seems reasonable from comments above, then its a rather nebulous concept. I'm now thinking OK, what are the circumstances which the test of proper course/close to the mark comes into play, since once she is in the zone it could be considered she is already close to the mark.
Blue and Yellow are approaching a mark to be left to starboard. What is the latest time Blue may luff?
Answer 1
Rule C2.9 (18.1) begins to apply when any part of the hull of either boat is in the zone. From this moment, if Blue luffs and thereafter has to bear away in order to give Yellow mark-room, then Blue breaks rule C2.9 (18.2(a)(1)). Blue does not break rule 18.2(a)(1), if she is able to luff while giving mark-room. Yellow is required to keep clear under rule 11. However, she is exonerated by rule 43.1(b) if she, while sailing her proper course to round or pass the mark, breaks rule 11 because Blue fails to give her mark-room.
Question 2
If Blue has to bear away to give mark-room, when is she required to do so?
Answer 2
Blue is required to bear away promptly from the moment the first of the boats is in the zone.
Similar answer in TR A 6. Just the rounding is to Port.
Kim
The mark in question is not a "starboard rounding" ... it's a "starboard passing". Please see my comments to David later in this thread. It is a mark of the course.
to round orpass the mark on the required side, and(c) to leave it astern.
IMO, Blue only has to give Yellow room to pass the mark, while Yellow maneuvers promptly in a seamanlike way ... that can be a different course than passing the mark promptly.
Blue is fine, IMO, if she maneuvers and continues on a trajectory toward the mark into the zone and leaves Yellow room to pass the mark on the proper side, as long as during her maneuvers, she leaves space for Yellow to maneuver promptly in a seamanlike way.
If we agree with Drawing 7/Answer 3 in Case 130 ... that has broader implications I feel (it's a spydie-sense feeling at this point ... so will take some thought to see if they (broader implications) actually exist and then to shake them out the tree).
I would have thought when P reaches the zone in this situation, since her proper course is not to sail close to the mark, ALL she is entitled to with respect to that mark is the space she NEEDS to pass it on the required side (and then to leave it astern), this space being enough so that she doesn’t have to make an unseamanlike manoeuvre, but not so much space that she can manoeuvre at her leisure - she must act promptly.
that there is some false logic involved in D7/A3.A similar situation is when a leeward-outside boat at a downwind buoy must give a windward-inside boat mark-room. We don't allow that mark-room to include unlimited space, just the space the inside boat NEEDS to round. That phrasing is right there in the definitions.
Add: apologies for seemingly putting words in others mouths. That was not my intention.
Fleet racers only get proper course if their PC is to sail close to the mark.
Match Racers get proper course to round or pass the mark, and room to pass a finishing mark after finishing.
Fleet Racing Racing Definitions
Mark-Room Room for a boat
(a) to sail to the mark when her proper course is to sail close to it,
(b) to round or pass the mark on the required side, and
(c) to leave it astern.
Match Racing Definitions
C2.2 The definition Mark-Room is changed to: Mark-Room Room for a boat to sail her proper course to round or pass the mark, and room to pass a finishing mark after finishing.
https://www.ussailing.org/wp-content/uploads/2025/06/Appeal-130-June-25-2025.pdf
https://www.ussailing.org/wp-content/uploads/2025/06/Appeal-130-June-25-2025.pdf
IMO, if one applies the methodology described/implied in US20, Case 75 and Case 118 to US130 D7/A3, the boat on starboard is providing the port, MR-entitled boat ample room to pass the mark on its proper side and to leave it astern ... prior to the starboard boat altering course.
Kim that call has them rounding the mark to starboard. That's a significantly different scenario than a passing mark off the rhumb-line between 2 rounding marks.
Kim:
The OP course has the mark also passing to Strb. The principal of R 18 begins to apply when at least one of them is in the zone. The OP make it clear that the mark is a mark of the course and R 18 applies: ..."blue has luffed yellow into the zone, so RRS18 switches on, and yellow is entitled to mark room."
As Angelo said: 'this is every day in the office (for J-105's)', blue is happy to sail this course, off the rhumb-line.
The MR and TR calls are good illustration of how the boats are expected to behave when they reach the zone overlapped. The definition change of MR in match or team race has not much to do with the principal in this post. No need to dive in that rabbit hole.
It's been my experience that in cases/calls where the mark is not a rounding-mark, a straight arrow is used with the text "direction to next mark" (or something to that effect) ... and that a curved arrow is used to indicate a rounding-mark.
The difference being highlighted in this discussion is in the instance where it's a passing-mark and the boats' positions are such that neither boat's proper course would take them close to the mark ... and thus the "sail to the mark" component of mark-room does not apply.
The picture is the MR call. Do not get stuck on the arrow. Take it out of the picture and you have a passing situation. All the language of R 18 applies and boats should treat it as such.
I am under the impression that the OP is asking:
"Can blue continue luffing yellow, and if so how far? Can she take yellow way to starboard of the mark provided she states her intention is to eventually permit yellow to pass the mark on the required side?"
The MR and TR calls say that the blue boat cannot sail the way the question is asked from the time the first boat is in the zone.
I do not see any Rules that change that.
Kim
That is not correct.
Please see J2.1(4) and def: sail the course (b)(1)
"Rounding marks" are a subset of marks that the string must both pass and touch, out of the larger set of marks that the string must simply pass on a specified side. We commonly refer to those marks, that have a passing-side but are not designated as rounding marks, finishing/starting-marks or gate-marks, as "passing marks".
But even in those instances, it is also common for the same SI's to list a series of channel/shoal/gov't marks and state that for all courses they "shall be passed/left on their channel side". So, depending upon which course the RC chooses, these marks can become passing marks that the string may or may not touch. As US103 points out, just because the string touches a mark, does not make it a rounding mark. The SI's must designate a mark as such.
So it's important to read your SI's carefully.
With all this discussion of passing and rounding marks, I want to highlight one of the important aspects of rounding marks. Rounding marks are one of the few places that an RC can shorten a course and finish. For instance, looking again at US103, since the SI's did not identify any of the marks as rounding marks, it would have been an error if the RC shortened or changed the course at any of the marks.
This is important as sometimes you can have marks designated as rounding marks that the string touches but does not "wrap" around it. In those instances, depending upon the wind direction, the lay lines may be such that a boat may decide for strategic/tactical reasons to sail a course that does not bring them close to the mark (staying close to shore out of current for instance). Boats that do that run the risk that the RC might finish at that mark.
Therefore even though an advantageous layline may not take you close to the mark, it's a good idea, if there is any chance the race would be shortened, to sail at least close enough to all rounding marks so that you can see if an RC boat is there ready to finish.