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Keep Clear boat question

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Sam.Spoons View Drop Down
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Post Options Post Options   Quote Sam.Spoons Quote  Post ReplyReply Direct Link To This Post Posted: 07 Sep 18 at 8:49am
Originally posted by Brass

Originally posted by Sam.Spoons

At pos 1 Blue is to windward of Red so must be keep clear boat (as would be the case in the original situation, if Blue was not sailing by the lee Yellow would be leeward boat and have RoW. 

Sam, the difficulty with this analysis is that the rules don't use the term 'to windward':  they define leeward side and windward side and and go on to define leeward boat and windward boat by the attribute 'being on the leeward side'

@1, see the analysis above in response to Mozzy:  being upwind does not make B a windward boat according to the definition.

No I understand that and the way the digram is drawn shows Yellow dead ahead of Blue in pos 1 so the explanation holds up. In the second scenario (between Red and Blue) Red is clearly on Blue's Leeward side at all times, Blue, in pos 1, is on Red's Windward side until she crosses ahead at 'pos 1.5' would this not be the 'last point of certainty' (I haven't forgotten that the term does not apply in the RRS for fleet racing)? At that point IMO the boats would be less than 2 boat lengths apart and the give way boat should already have taken some action to avoid a collision. Do the rules allow a GW boat to anticipate a change in RoW status? If not I would have though a PC would be right in penalising Blue (but not Red) for failing to keep clear.

This is interesting as I expect to meet Lasers sailing by the lee with some regularity over the winter series' and some of them will undoubtedly have read this thread. So if I am Blue (in either scenario), I would be wise to keep clear of the close hauled boat. If Red I would, I think, hold my course and possibly hail "Windward boat", but what should I do if I was Yellow?

BTW, in both cases at P1 (assuming the drawing is to scale) the boats are less than 3.5 boat lengths apart, in anything more than F2 this would make the boats less than 5 seconds from contact (14 metres, both travelling at around 1.5 m/s in more or less opposite directions). I'd say the decision to take avoiding action or not needs to be taken no later than P1?


Edited by Sam.Spoons - 07 Sep 18 at 8:59am
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Post Options Post Options   Quote Brass Quote  Post ReplyReply Direct Link To This Post Posted: 07 Sep 18 at 8:55am
Originally posted by Rupert

So, if this went to protest, how many club protest committees would look at it and bin the upwind boat?

The point I was failing to make earlier wasn't to do with sailing by the lee, but of the difficulty boats closing on each other would have in calculating that the boat upwind wasn't the boat to windward, so making this a virtually impossible situation to spot, especially in a mixed fleet. I'm sure Laser sailors are getting used to such situations??

And that the upwind boat can become windward boat with a very small change of wind direction. Though this one makes my head hurt.

Firstly, this is an old chestnut that crops up in a rules forum once every couple of years or so.   It is a 'puzzle question':  it's hypothetical;  it's not as if it's ever been protested in reality much less taken to Appeal or a WS Case.

In practice, I would expect Y, close hauled on starboard to be expecting to have right of way on the whole world, and as Y sees B coming, Y will be hailing 'leeward boat here', and B, knowing that she is on a dead run and should normally be giving way to boats close hauled on the same tack to keep clear of Y without any argument.  Unless one of them has recently read a thread on an internet forum, they're not going to get to the nobody required to keep clear conclusion on the water.

If it came to a protest, lets consider two scenarios:  Y changes course, avoids contact and protests B, and neither boat avoids, there is contact and one of them (probably Y) protests.

Y changes course, avoids contact and protests

The protest committee's conclusions are really going to depend on the evidence the parties bring and the argument and application of the rules that they contend for.  If Y has a picture in her mind of close hauled boat and boat running on the same tack, her evidence might very well suggest that B was not by the lee, and was clearly windward.  Who knows what B might say.

I'd have to agree with you that I would expect many protest committees (not having read any internet forums recently) to conclude that B broke rule 11.

No change in course and contact

Again, this is going to be driven by the 'picture' the parties portray in their evidence, and how well each argues her case.

As above, I'd really expect a protest committee to conclude that B broke rule 11 and 14.

Remaining issue is whether Y broke rule 14 and if so, whether she was exonerated.  If B was jinking around on waves ad Y was doing the dance of death, then maybe she would get off, otherwise, there's nothing to have stopped Y changing course and avoiding contact, and Y breaks rule 14.

As to the difficulty of a boat, even being aware of this difficult application of the rules, accurately perceiving the relationship with other boats, see my reply to Mozzy above:  Initially it may be that the boats are so far apart that it is not possible to say that one is 'on the leeward side of the other. That's unfortunate, but it sometimes happens and as JimC has pointed out, the cure would probably be worse than the disease. 
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Post Options Post Options   Quote Sam.Spoons Quote  Post ReplyReply Direct Link To This Post Posted: 07 Sep 18 at 9:32am
This could be solved by adding 'rule 12.5' "On The Same Tack on different legs of the course, a boat sailing a downwind leg shall keep clear of a boat sailing an upwind leg"? The only place where there may be ambiguity would be where the legs are slightly either side of a beam reach but boats on different legs and converging would either be on opposite tacks to travelling in substantial the same direction so rules 10, 11 or 12 would cover the situation.

Edited by Sam.Spoons - 07 Sep 18 at 10:39am
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Post Options Post Options   Quote Brass Quote  Post ReplyReply Direct Link To This Post Posted: 07 Sep 18 at 9:46am
Originally posted by andymck

For both scenarios
 Why is this not rule 15?
For the first scenario B and Y passing starboard to starboard, neither boat is required to keep clear of the other, neither boat acquires right of way - that's the gateway to rule 15 - rule 15 does not apply.

For the second scenario R and B passing port to port, both boats required to keep clear, rule 15 is a candidate, but the diagrams haven't taken the facts as far as when and how an actual breach occurs.

The blue boat acquires a technical right of way between position 1 and 2. With the closing speed, this is likely to very close to the time that one of them would need to start keeping clear. 

I take it we're talking about R and B passing port to port.

There's no such thing as 'a technical right of way'.  Either a boat is required to keep clear or she is not.

I think that once one boat becomes required to keep clear (because 'on the leeward side' is resolved), then the other becomes required to keep clear at the same time.

So each boat is required to keep clear of the other and, possibly, each boat is required to give the other room to keep clear.

I think that if a boat keeps clear of another boat, then there must have been enough room for the other boat to have kept clear.

If I'm missing the point you are trying to make, how about describing some more facts about what happens next after @2.

We would also probably resort back to the last point of certainty in a protest meeting?

What is the difficult fact that you would be trying to resolve applying last point of certainty?
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Post Options Post Options   Quote JimC Quote  Post ReplyReply Direct Link To This Post Posted: 07 Sep 18 at 12:36pm
As Brass points out its basically a puzzle.
Even if this rather unlikely scenario comes up, and it is unlikely really, it seems to me that the key things are:

There is no circumstance in which the running boat has right of way, and the running boat is always obligated to avoid contact. From the running boats point of view the only difference is the subtle one between being required to keep clear and being required to avoid contact.

Similarly the beating boat only needs to be aware that it is just possible that they may get in a situation where they don't actually have right of way, and in that case if they fail to avoid a collision they will not get exonerated.



Edited by JimC - 07 Sep 18 at 12:45pm
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Post Options Post Options   Quote JimC Quote  Post ReplyReply Direct Link To This Post Posted: 07 Sep 18 at 12:40pm
Originally posted by Rupert

And that the upwind boat can become windward boat with a very small change of wind direction. Though this one makes my head hurt.


I don't get where you're coming from on this Rupert. The whole point of the definition about leeward and windward sides of the boat is that small changes in wind direction don't make any difference. Its the direction of the boats that makes the difference.



The situation where no neither boat is to leeward happens all the time, as seen from this sketch. But the point is that in most cases the boats will not be on a collision course, so we don't care. In my sketch only one of the 4 running positions is on a collision course with a boat on its windward side.

For the pedantic, this sketch is only intended to show 3 boats, one of them in 4 positions.

Edited by JimC - 07 Sep 18 at 1:21pm
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Post Options Post Options   Quote davidyacht Quote  Post ReplyReply Direct Link To This Post Posted: 07 Sep 18 at 6:01pm
Thanks Jim, a picture tells a thousand words ... from a practical point of view I shall continue to hail “starboard close hauled” on the basis that 99% of the time I was entitled to do so, and on the 1% that it is a precursor to who is to make the first move of the “dance”.
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Post Options Post Options   Quote Rupert Quote  Post ReplyReply Direct Link To This Post Posted: 07 Sep 18 at 7:36pm
Thank Jim, head hurts less. Cider says it will hurt again in the morning...
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Post Options Post Options   Quote andymck Quote  Post ReplyReply Direct Link To This Post Posted: 17 Sep 18 at 10:39am
So. It actually happened on Saturday.
Team race course. Mark trap situation. Both on a broad reach.
Blue windward was 1.5 boat lengths to windward boat bore away hard to get round the back of yellow so ended up significantly by the Lee.
Yellow saw and luffed very hard beyond close hauled.
Windward to windward contact occurred.
Initially we felt the change of course was too aggressive as the blue windward boat had been passing behind yellow boat. After we looked at it again with the magnetic boats an we realised this was windward to windward contact.
I will try to draw it later.


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Post Options Post Options   Quote JimC Quote  Post ReplyReply Direct Link To This Post Posted: 17 Sep 18 at 12:32pm
Sounds as if the biggest challenge might be to figure out who broke most rules! I'll be intrigued to see the drawing. Case 30 might be of interest as demonstrating that one may have broken rules before a collision occurs, even if one has ROW when the contact happens, but team racing is so specialised that I'd be silly to offer opinions.
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