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Tacking on a mark, room to keep clear?

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Post Options Post Options   Quote Guests Quote  Post ReplyReply Direct Link To This Post Posted: 21 May 19 at 2:18pm
Originally posted by Fatboi

 If a boat is clear ahead when she reaches the zone, the boat clear astern at that moment shall thereafter give her mark-room."
Made the important part red. Does this not mean that the boat clear astern (Not overlapped at 3) shall give mark room and therefore allow the leading boat room to round?
18 is is turned off as soon as you cross head to wind. So no, as soon as you cross head to wind the boat following in does not have to give you mark room.

Originally posted by Fatboi

As the leading boat tacks and they are on a close hauled course, they are then on STBD, and so the following (Port) boat must still keep clear.
Yes, they are on starboard. But, despite being instantly on starboard they are keep clear boat (rule 13 - While taking) until on a close hauled course. Then when they get to close hauled they acquire right of way... but are subject to rule 15 so have to still give the port boat room to keep clear. 

Originally posted by Fatboi

If you are coming in on a 'fat lay' they surely would not be overlapped and would be following you in, so shouldn't really be too much of a drama. 
The boats are about 5m long then crews will be 3.5 off centre. So you'd need to do about 8.5m in the time it takes them to close the gap on you. 

Looking at a few tack on the entry we drop dramatically from 10 to 2 knots. So taking a high average of 6.5 knots it would take 2 second to clear the distance you need. In 2 seconds a boat doing 12 knots will do 12m... 


Edited by mozzy - 21 May 19 at 2:32pm
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Post Options Post Options   Quote Fatboi Quote  Post ReplyReply Direct Link To This Post Posted: 21 May 19 at 3:31pm
It is all sounding very situational... Mainly depending on how close the boats are on the way in.

The tacking boat only has to get to close hauled and they are then right of way boat again. You do not have to be back to full speed or sailing, so even if doing 2kts close hauled, technically you are right of way. 
All you need to do is give room to keep clear - they could duck you. 

I guess it is all risk management.
Do you need to take that risk that there will be an incident? Probably not, if so and its tight, let them round and then follow round...

If you are the boat following, can you prove you had an overlap at 3, or can you prove they had not completed the tack? If not, follow round... 
If you hit them while they tack and your trying to avoid - they didn't give you room to keep clear. 

The other point is as soon as you realise you are getting into this scenario up the beat, take a high mode to ensure they need to follow your line in directly behind you. 
At 3 BL hail 'no room', I am sure they will back off. If not, a slow head up into the wind as you get to the mark will show their intentions. If they come inside you they have no right... 
Don't tack, just slowly head up... They will probably hit you and/or the mark and they are clearly in the wrong.
Hopefully when you hail no room, they will back off and either follow in or bear away, so that they can get a good tack and rounding.




Edited by Fatboi - 21 May 19 at 3:34pm
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Post Options Post Options   Quote Brass Quote  Post ReplyReply Direct Link To This Post Posted: 21 May 19 at 10:31pm
Originally posted by mozzy

18.1 turning off rule 18 for boats on opposite tacks on a beat makes complete sense. It stops port boats coming in on the layline. I know that happens at leeward marks, but there starboard boats can just bear away a little to afford room. Up wind they cannot head up without stopping and causing a pile up.  

However, the way it's worded seems to have some strange implications for boats reaching in to mark they shall tack around. 

18.1 a) specifically makes the opposite tacks exemption for boats on a beat to windward... but then 18.1 b) seems to make opposite tacks exempt all the time.  

Does the diagram below change your rules interpretation? And if not, then what is the purpose of rule 18.1a)?

Without bursting my boiler trying to think of a counter example, I'm inclined to think that you 're right and that rule 18.1b does all the work that rule 18.1a does.

I think the reason for rule 18.1a is that it has always been there, it is simple and memorable.  Rule 18.2b was added later to solve problems with close reaching marks.

I'm not the Racing Rules Committee, I don't 'interpret' rules.  I just apply them.

I don't see any problem with the diagrammed scenario.

@4 Y has passed head to wind, and loses her entitlement to mark-room because  rule 18 ceases to apply (rule 18.1b),

Y is required to keep clear of B (rule 13).

B is not required to give Y room to keep clear because B acquired right of way because of Y's action in tacking (rule 15).

Looks to me like Y has caused her own problem by sagging down below the layline:  she would have done better to hold her lane close to the mark and wiped B off on the mark.

I'm not really familiar with HP dinghys, but I think it's up to you to devise tactics that work for your boats:  I don't think the rules are 'causing' the problem.


Edited by Brass - 21 May 19 at 10:39pm
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Post Options Post Options   Quote Guests Quote  Post ReplyReply Direct Link To This Post Posted: 22 May 19 at 7:58am
Thanks

I guess it's just about having a few of these situations figured out ahead of time. 

The slow tacks in the 800 change the boat on boat strategy quite a bit in terms of where you need to be relative to other boats to complete. It changes some of the 'set moves' from the 200 quite a bit. 
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Post Options Post Options   Quote Brass Quote  Post ReplyReply Direct Link To This Post Posted: 22 May 19 at 2:00pm
Would it be worth talking/reading tactics from planet multi to get some ideas?
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Post Options Post Options   Quote GML Quote  Post ReplyReply Direct Link To This Post Posted: 24 May 19 at 9:17am
Originally posted by Brass

Originally posted by mozzy

18.1 turning off rule 18 for boats on opposite tacks on a beat makes complete sense. It stops port boats coming in on the layline. I know that happens at leeward marks, but there starboard boats can just bear away a little to afford room. Up wind they cannot head up without stopping and causing a pile up.  

However, the way it's worded seems to have some strange implications for boats reaching in to mark they shall tack around. 

18.1 a) specifically makes the opposite tacks exemption for boats on a beat to windward... but then 18.1 b) seems to make opposite tacks exempt all the time.  

Does the diagram below change your rules interpretation? And if not, then what is the purpose of rule 18.1a)?

Without bursting my boiler trying to think of a counter example, I'm inclined to think that you 're right and that rule 18.1b does all the work that rule 18.1a does.
18.1(a) applies at a passing mark, upwind gate or upwind finish whereas 18.1(b) may not.
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Post Options Post Options   Quote Brass Quote  Post ReplyReply Direct Link To This Post Posted: 24 May 19 at 9:44am
Could you elaborate a bit please?
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Post Options Post Options   Quote GML Quote  Post ReplyReply Direct Link To This Post Posted: 24 May 19 at 1:12pm
Originally posted by Brass

Could you elaborate a bit please?
I assume you mean me Brass...

The question as I understood it was why bother with RRS18.1(a) when RRS18.1(b) would seem to do the same job. My point was that whilst that may be true at a windward mark, it may not be true at a mark on a beat that is not a windward mark - the most obvious example being a finish mark, but other examples include a passing mark on an upwind leg and a gate halfway up a beat (for example where boats have to pass through the start/finish line on each lap). In that case RRS18.1(a) still applies, but RRS18.1(b) may not, as neither boat may need to tack at the mark to sail their proper course - they may be able to just keep sailing upwind on the same tack.

So in the following example I believe RRS18.1(a) applies but RRS18.1(b) does not (assuming this is the finish line):


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Post Options Post Options   Quote Guests Quote  Post ReplyReply Direct Link To This Post Posted: 24 May 19 at 2:07pm
So i guess you'd start with a basic rule that covers all situations of:
"However, it does not apply between boats on opposite tacks"

But that alone would be too broad and would include boats on opposite tacks downwind (opposite 'gybe') and have unintended consequences for leeward / gybe marks. 

So they add 'on a beat to windward' to avoid the above.   

But adding that leaves a grey area for reaching legs that are ended with a tack. As these are not really a beat to windward, but you do end up with boats on opposite tacks at the mark. So they add 18.1 b) 'between boats on opposite tacks when the proper course at the mark for one but not both of them is to tack'... which covers the tiny instance after you've tacked to fetch around a mark you have reached toward on the opposite tack. But also seems to have a lot of duplicity with 18.1 a).

In the real world I see no reason why a boat clear ahead and on the same approach tack shouldn't be given room to round the mark ahead / inside, even if that includes a tack. But finding a way to word that without giving mark room to port tack approaches is hard.  I think some of the difficulty comes from 'tack' the verb not being defined. 

If the verb was defined as the time between head to wind and close hauled (as implied by rule 13), and room was given for that 'tacking' then you'd escape this ridiculous situation where a boat first entitled to mark room then right of way is the keep clear boat for 45 degrees of turn, despite that turn being completely predictable by all boats around.  
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Post Options Post Options   Quote Brass Quote  Post ReplyReply Direct Link To This Post Posted: 24 May 19 at 2:25pm
Originally posted by GML

Originally posted by Brass

Could you elaborate a bit please?
I assume you mean me Brass...

The question as I understood it was why bother with RRS18.1(a) when RRS18.1(b) would seem to do the same job. My point was that whilst that may be true at a windward mark, it may not be true at a mark on a beat that is not a windward mark - the most obvious example being a finish mark, but other examples include a passing mark on an upwind leg and a gate halfway up a beat (for example where boats have to pass through the start/finish line on each lap). In that case RRS18.1(a) still applies, but RRS18.1(b) may not, as neither boat may need to tack at the mark to sail their proper course - they may be able to just keep sailing upwind on the same tack.

So in the following example I believe RRS18.1(a) applies but RRS18.1(b) does not (assuming this is the finish line):



Thanks, great, very helpful.
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