Windward mark: Both must tack
Printed From: Yachts and Yachting Online
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Forum Name: Racing Rules
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URL: http://www.yachtsandyachting.com/forum/forum_posts.asp?TID=6715
Printed Date: 07 Aug 25 at 8:42pm
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Topic: Windward mark: Both must tack
Posted By: damp_freddie
Subject: Windward mark: Both must tack
Date Posted: 12 May 10 at 11:58am
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Hi I have still this bugging little rules question if someone could answer: port rounding, windward mark Port Boat enters the three boat zone before Stb, but on a collision course: both must tack to get around- how does 18 apply? Is Port actually overlapped from outside the zone ? |
Replies:
Posted By: JimC
Date Posted: 12 May 10 at 12:12pm
| Surely Rule 18 doesn't apply if boats are on opposite tacks on a beat to windward. |
Posted By: damp_freddie
Date Posted: 12 May 10 at 12:14pm
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Yeah, So if Port tacks without causing Stb to alter course and then both must tack twice again? Port was within the 3 zone and not overlapped? Or does the different tack automatically overlap transom to bow? |
Posted By: JimC
Date Posted: 12 May 10 at 12:25pm
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I can't figure out the situation you are puzzled about.
Rule 18 doesn't apply while boats are on opposite tacks so Port must keep clear and must either duck S or tack before they reach S. If P ducks S tacks and has mark room, if P tacks S has mark room. |
Posted By: gordon
Date Posted: 12 May 10 at 7:58pm
Gordon ------------- Gordon |
Posted By: damp_freddie
Date Posted: 13 May 10 at 11:59am
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Thanks Gordon The new clarification to 18 in 2010 helps with this because P now passes head to wind and loses her rights to water. 10-17 govern. I may go and do a diagram. This happens all the time where I sail at the moment due to some fairly narrow channels restricting the fleet and forcing people into the "death slot" |
Posted By: gordon
Date Posted: 13 May 10 at 12:43pm
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A diagram would help, because as I read your initial post P never had any right to mark room. Unless of course S tacks below P and ends up on port overlapped outside P. Gordon ------------- Gordon |
Posted By: damp_freddie
Date Posted: 13 May 10 at 3:25pm
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the complication is 18.1.b one of the exemptions to the rule: "on opposite tacks....proper course for one but not both of them is to tack" This has always seemed strange to me: it should be overiden by 18.1.a, so why is it still there? As Elvstrøms' states: on opposite tacks it is as if the mark is not there: 10-15 apply most. Also I think it is superflouos with 18.2.b : the reference from a. is useless now: "a" and "b" should either just be merged or b should state the obvious, when the overlap is NOT before the (3 boat) zone. These all seem to be hangovers from earlier versions which could be further simplified. |
Posted By: gordon
Date Posted: 13 May 10 at 5:09pm
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1; Boats may be on opposite tacks but not on a beat to windward - take the case of a reaching leg where one boat has gone too deep and has to tack back up to round mark. 2. 18.2b applies when there is an over lap, or one boat is clear ahead when the first boat reaches the zone. When boats are on opposite tacks on an upwind leg (which might not be a beat) then, by definition they are neither overlapped nor clear ahead/astern. When one boat enters the zone 18.2b does not apply, indeed none of rule 18 applies. If later, boats become overlapped on the same tack, rule 18.2a will apply. Remember, 18.3 only applies if one boat is fetching the mark. So, at a port hand windward mark, if starboard tack boat is below the lay line, crosses the port tack boat and tacks in to an overlap to windward 18.3 does not apply as neither boat is fetching the mark, 18.2b does not apply, so 18.2a applies and windward inside boat is entitled to mark room (including room to tack). Gordon 18.2a is a default rule that applies when one of the other parts of the rule do not apply. ------------- Gordon |
Posted By: Brass
Date Posted: 14 May 10 at 1:39am
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Is the diagram at the foot right? Starting point P on Port, S on Stbd, boats on opposite tacks with courses intersecting between one and two boatlengths downwind of the mark. P reaches the zone first. @1 when P reaches the zone, rule 18 does not apply (rule 18.1(a)). Both needing to tack is irrelevant. Boats are NOT overlapped because boats are on opposite tacks and rule 18 does not apply (Definition: Overlap). @2 minus Delta, when P, tacking, passes head to wind, Boats are now on the same tack. Rule 18 applies. NOT rule 18.2(b) because boats were neither clear ahead nor clear astern, nor overlapped when P reached the zone. NOT rule 18.3 because S was not fetching, so only rule 18.2(a): while they are overlapped, whichever boat is outside boat, at any future instant shall give the inside boat mark-room. BUT it may be that, initially S is not 'inside' between P and the mark, so rule 18 is turned on, but it has no 'content': neither boat gets a right to mark-room. @2+Delta, both boats on Stbd, and S, to windward of P, gets between P and the mark, S is now 'inside' P and P must give S mark-room. With P starting at the edge of the zone @1, by now S is well inside the zone, and is in all likelihood 'at' the mark, so P must give S room to sail her proper course to round the mark. S is overlapped to windward and on the inside of P so the mark-room P is required to give includes room for S to tack. @3 minus Delta, S tacking from Stbd onto Port, passes head to wind, boats are now on opposite tacks, still on a beat to windward, so rule 18 goes OFF, P, now on Stbd tack is RoW boat, but, boats are on diverging courses, so this is immaterial. @3+Delta, P tacking onto Port, passes head to wind, boats now on same tack, rule 18 comes ON, specifically rule 18.2(a), and if P becomes overlapped inside S, then S must give P mark-room, by now, certainly being room to sail her proper course at the mark.
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Posted By: gordon
Date Posted: 14 May 10 at 4:44pm
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n the scenario in the diagram S should stand on and sail beyond the mark, as she is entitled to do as long as she keeps clear of P (once P has tacked). She can then tack and bear away, leaving herself clear ahead and able to round the mark on port, luff hard and tack without P being able to prevent her. Obviously S didn't do much team racing at college! Gordon ------------- Gordon |
Posted By: piglet
Date Posted: 16 Oct 12 at 4:52pm
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I'll recycle this old post as it is similar but different to my (sons) scenario.
Radial & Merlin both on starboard but both below the layline due to light wind and foul tide.
Merlin overtakes Radial to windward, Radial tacks onto port and crosses Merlins stern. Merlin tacks onto port. Merlin reaches the zone before Radial though not sure when, boats must have been overlapped when on port. Radial then tacks back onto starboard on the layline, has gained through the tacks and hails starboard. Merlin tacks, there is no boat contact but Merlin ends up wrapped round the mark and most displeased with Radial.
My guess is the Merlin had rights to room but I'm not sure why?
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Posted By: JimC
Date Posted: 16 Oct 12 at 5:46pm
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I can't make your description work with who was ahead where, but my impression is that Merlin had no rights.
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Posted By: piglet
Date Posted: 16 Oct 12 at 6:21pm
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Thanks Jim, sorry if my description is a bit woolly.
Basically both approached on starboad then both onto port then both back onto starboard again with Merlin stuck on the mark and Radial sailing away.
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Posted By: MattK
Date Posted: 16 Oct 12 at 7:31pm
| If the merlin was overlapped on the radial when they entered the zone on port, the radial had to give the merlin room, if it didn't the merlin had no rights to water |
Posted By: JimC
Date Posted: 16 Oct 12 at 9:00pm
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Gordon and Brass are much better at this stuff than me, but I'll have a shot...
Case 95 in the case book: http://www.sailing.org/tools/documents/CaseBook20092012updatedNov2011-[11669].pdf is probably one to look at. So approaching the zone the boats are on port tack and M is to windward of and thus inside R. R is Right of way boat, but M has mark room. R then tacks. First question: did R complete her tack in accordance with Rules 10 and 13 - ie M did not have to start to take avoiding action until R was on a close hauled course. If R fouled M then R is toast. OK, now (see Case 95) M is no longer entitled to mark room because they are on opposite tacks. R is ROW boat and its plain port/starboard. M mst tack (or go behind R) and does so. Now M has tacked in the zone so 18.3 applies (still reading Case 95). So the next question is whether M completed her tack without breaking Rules 10 and 13. Because they were on opposite tacks at the time with no mark room involved then I think if M had to tack below the lay line that was just tough. If, after the tack, still noone has fouled anyone, now both boats are on the same tack, in the zone, and M is inside boat. Rule 18.3 still applies because there was a tack in the zone. Now we lose Case 95, but as I see it, although M is now sort of entitled to mark room again, 18.3 means that she cannot sail a course that pushes R above close hauled. If that means M can't get round the mark I think that's tough again. So I think it all hangs on where and how R tacked. If the Radial tacked smack on the lay line and without fouling the Merlin then the Merlin is out of luck. The trouble I am having with this is that from my image of what happened I don't really see that the Radial could have been far away enough from the Merlin to put a legal tack in, bearing in mind that a few seconds before they had been ducking transoms. If the Radial didn't have room to put a tack in then their only choice was to wait until the Merlin tacked. |
Posted By: sargesail
Date Posted: 16 Oct 12 at 9:07pm
| I'd agree with that - and add for amplification that if the Merlin did not start her tack until the Radial was tack complete, yet managed to not hit/be hit by the radial then by performance she proves the radial's tack to be legit...and the Merlin can have no complaints.....if on the other hand the Merlin had to start the tack before the radial was tack complete then it's time for the Protest Room. |
Posted By: Brass
Date Posted: 17 Oct 12 at 2:39am
Pretty good analysis right up until here.
M is not entitled to mark-room.
The only two rules that confer mark-room are rules 18.2 and 18.3. When rule 18.3 applies (when a boat tacks in the zone while another is fetching), rule 18.2 does not apply (rule 18.3). So the only applicable entitlement to room is that provided in rule 18.3( b ), which is an entitlement for the fetching boat (in this case R), to mark-room if she becomes overlapped inside M. Here M is overlapped inside R, so neither boat is entitled to mark-room.
M is the leeward overlapped right of way boat (rule 11), so if R bears away on top of her, R breaks rule 11. By virtue of her right of way, R, keeping clear to windward of M should allow M to get around inside her.
M is subject to a limitation under rule 18.3( a ) that she shall not prevent R from passing the mark on the required side, so she may need to bear away around the mark pretty quickly so as not to 'prevent' R from passing it
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Posted By: JimC
Date Posted: 17 Oct 12 at 8:42am
OK, you need to explain that to me a bit more... I see the non-applicability of 18.2, that's clear enough, but the first bit of 18.3a troubles me.
My emphasis. Assuming that R was smack on the lay line, then in order to get a Merlin (which is some 7 feet wide) round the mark it seems to me that the R is likely to be pushed way above close hauled if the boats are overlapped. So although windward must keep clear, I don't see why that entitles L to luff up to get round the mark if in doing so W must sail above close hauled. Doesn't the restriction on forcing above close hauled continue until the are out of the zone as well as the rstriction on preventing from passing the mark? But I guess we need a few more facts here again. Were M and R overlapped after M completed her tack? Was M on the layline or below it? Why did M get tangled in the mark? Was it avoiding a collision because R didn't keep clear, or was it, with little way on after tacking and (possibly) below the lay line, they plain couldn't get round the mark? Did R have to sail above close hauled at any time to keep clear? Was R bang on the lay line or above it? Was there enough room between M and R to get M round the mark? |
Posted By: piglet
Date Posted: 17 Oct 12 at 11:30am
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I must confess to being 110 miles away at the time, but, based on my understanding of the scenario:
JimC wrote: The trouble I am having with this is that from my image of what happened I don't really see that the Radial could have been far away enough from the Merlin to put a legal tack in
R maintains he tacked outside the zone and that M had plenty of time to respond after R hailed.
I suspect M may see it differently, but M did manage to tack without boat contact.
Were M and R overlapped after M completed her tack? Was M on the layline or below it?
Yes they were overlapped, M never made it to the layline.
Why did M get tangled in the mark? Was it avoiding a collision because R didn't keep clear, or was it, with little way on after tacking and (possibly) below the lay line, they plain couldn't get round the mark?
M was forced to tack early to keep clear of R and plain couldn't get round the mark.
Did R have to sail above close hauled at any time to keep clear?
No, R stood on, he doesn't pay the bills. Was R bang on the lay line or above it?
Bang on.
Was there enough room between M and R to get M round the mark?
No, R had shut the door.
Don't forget the tide pushing them both back towards the mark, hence M's predicament.
Thanks chaps, this is good.
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Posted By: Brass
Date Posted: 17 Oct 12 at 2:43pm
Quite right, assuming R was smack on the lay, except:
But it's just your assumption, not in the original scenario, that R was smack on the layline: she might just as well have bee a bit above it.
Correct. L/M isn't. It does.
To help maintain our sanity, and avoid endless chains of speculation, there's a convention in judges exams that if the original scenario doesn't contain the facts necessary to establish any particular breach of the rules, then to assume that the facts did not support that breach. Not always appropriate when answering web-posts, but we can probably rely on it here. R isn't complaining about anything, it's M getting upset about being 'forced' into the mark. Also, sometimes it isn't helpful to go exploring a possible breach that would have required a valid protest that probably wasn't hailed for.
All good questions if we want to get to a 'complete' analysis, and if answered, will readily lead to the right answers. |
Posted By: Brass
Date Posted: 17 Oct 12 at 11:03pm
Edit: Duh! didn't turn the page.
You can assume that R tacked bang on the lay, or you can assume R tacked a little above and M tacked a little below.
Or you can just assume that, since in the OP scenario, nobody is complaining about rule 18.3( a ), that it's a non-issue.
But you're quite right, if R is right on the layline, and she goes above M to avoid contact or to keep clear, then necessarily she is sailing above close hauled. All the more so if R is outside M and M herself sails above close hauled (allowing for the difference in 'close hauled' for each different type of boat).
And you are also right: the limitations of rule 18.3 apply while ever rule 18 applies, that is while ever one of the boats is still in the zone.
To solve the rules 'problem' that piglet asked, you don't really need to explore whether R might have broken rule 15, or rule 11. It suffices to apply rule 18.3 to identify the limitations on M as clear ahead or leeward right of way boat.
You asked 'Was there enough room between M and R to get M round the mark?'. Because there is no entitlement to mark-room (or any other kind of room under rules 15, 16.1, 19, or 20), whether there is room is irrelevant:
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Posted By: Patrick McCosh
Date Posted: 18 Nov 12 at 4:32pm
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Last Sunday the optimists approaching windward mark upwind leg all on port after a big windswitch to the left. No overlap at the zone, lead boat A is clear ahead. Lead boat A tacks onto starboard to round the mark and boat behind (B) collides into back of A before A completes her tack. Who is give way boat ? ------------- Patrick |
Posted By: RS400atC
Date Posted: 18 Nov 12 at 4:45pm
If B hit the back of A, that suggest to me that A was not yet head to wind, hence still had ROW. If A was clear ahead when she entered the zone, and entered the zone before tacking, B must keep clear. 18.2 b. |
Posted By: gordon
Date Posted: 18 Nov 12 at 5:11pm
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A on port enters the zone clear ahead. She is entitled to mark room (rule 18.2b), but mark room does not include room to tack. A passes head to wind and is subject to rule 13. She is no longer entitled to mark-room (18.2c). Until A reaches a close hauled course A must keep clear of B. As B became right of way boat by the actions of A, B is not required, initailly, to give A room to keep clear. There was contact between A and B. A broke rule 13 and should take a penalty. If there was damage to either boat, or injury and B did not attempt to avoid the collision B broke rule 14. ------------- Gordon |
Posted By: Brass
Date Posted: 18 Nov 12 at 8:02pm
Good get.
Not so good. At a windward mark, when one of two boats initially on the same tack (with rule 18 applying), changes tack by passing head to wind, boats are on opposite tacks on a beat to windward (or at least the proper course at the mark for one but not the other is [will be] to tack) and rule 18 ceases to apply altogether (rule 18.1( a ) or ( b )). |
Posted By: RS400atC
Date Posted: 18 Nov 12 at 8:25pm
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So, boat A, having passed head to wind, must keep clear of B until she is on a close hauled course, (R13). But if B alters couse during this time, R16.1 would mean A be given room to keep clear. Room to keep clear presumably might not allow A to bear off to close hauled, she might have to go back onto port? |
Posted By: Brass
Date Posted: 18 Nov 12 at 10:18pm
Yes, if it was possible for A to tack back onto port, she might be able to keep clear by doing that.
But with Optis, I would think that there would be a good chance that if A attempted to tack back, whe would end up in irons, right in the headlights.
I wouldn't want to be B in the protest hearing saying 'sure I hunted up and A could have kept clear by tacking back onto Port' unless these were boats that carried some way and I was sure that I could make a good case that tacking back in time to keep clear was possible.
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