Sometimes I think that formatting would help a lot in parsing these sentences.  At least in computers, 'and' and 'or' have the same precedence and you evaluate them left to right.  In this case if both sides of the 'and' are true then that side of the 'or' is true.  If either side of the 'or' is true then the whole thing is true.  I think the comma after 'leg' is supposed to help with how to read it.  Adding parenthesis can help:

Rule 18 no longer applies between boats when the boat entitled to mark-room has (left the mark astern and is on a course to begin sailing the next leg), or (is no longer racing).

It is probably clearer to write it this way:

Rule 18 no longer applies between boats when the boat entitled to mark-room has:
A) left the mark astern and is on a course to begin sailing the next leg
or
B)  is no longer racing

I would probably use the definition from match racing C7.2(c):

A boat completes a leg of the course when any part of her hull crosses the extension of the line from the previous mark through the mark she is rounding, or on the last leg when she finishes.

So in position 4, Rule 18 no longer applies, Blue has given Yellow mark room and Yellow no longer is exonerated if she breaks rule 11.

My reading, re-written in your style is thus:

Rule 18 no longer applies between boats when the boat entitled to mark-room 
has left the mark astern and is 
A) on a course to begin sailing the next leg
or
B)  no longer racing.

I can see that way to read it, but I have to believe that the comma is intentional and there to separate the stuff before the 'or' and after it.  It seems to me that this is a great example of an Oxford comma that is separating things in a list.  We have the A & B part as the first item in the list which is then or'd with the second item because of the comma.  Personally, I wish they would format the rule (and others like this) more as we have done than as proposed.  I think this makes the rule clearer to the reader.

Consider the following at the finish.  Is Yellow still entitled to mark room from Blue?  Has Yellow cleared the marks or is she still racing?  Since she hasn't left the mark astern Rule 18 would still apply.  The rules of Part 2 still apply but can Blue be penalized for breaking rule 18?  With your format it matters whether the mark is astern or not. in turning rule 18 off  With mine it only matters if she is still racing.  Maybe it really doesn't matter :-)

 

If Yellow has finished, she no longer has a Proper Course, which is all she was entitled to under TR18.
So, it does not matter whether she has the mark astern.

John/Phillip,

Thank you.  I agree that formatting and punctuation could be an approach to take to differentiate which clauses are which.  Rather than requiring the reader to be a grammatical expert, the sub-paragraphs are clear.  (I have a method which is clear, but does not rely on a perfectly positioned comma.  Later.)

I tend to agree with Phillip, in that the clause of 'no longer racing' can stand alone, but not only for the reasons of no proper course.  As defined, this term includes 'finished and cleared the line and marks'.  So it doesn't rely on the relative position of the marks to work. So >>>

a) left the mark astern and is on course to begin sailing the next leg
or
b) has finished
is no longer racing
<<< works for me.

Isn't that what the TR18.1(b) shows already with the comma placing?  It think so.

--------------------------------------

However, I still find the phrase 'on a course to begin sailing the next leg' intriguing.

I don't quite know what it means.

Consider:

a) has left the mark astern and is on a course to the next leg.

b) has left the mark astern and is beginning to sail the next leg.

c) has left the mark astern and is sailing the next leg.

These are three variations of the TR18.1(b) phrase, but I don't think any lead to a quantifiable moment in the absence of some clarification.

For what reason have the rule makers arrived at the combo phrase they have?  There must be a reason. Does their phrase yield a quantifiable moment in space and time, which sailors can actually see and note, or is it still essentially a subjective issue like the 'has been given mark-room' of before?

You are right about not being able to determine a specific point in time when you begin to sail the next leg with the new rule as written.  That's why I would add the match racing definition.  If you are across the line then you are on the next leg.  It is a quantifiable moment in time that the sailors can point to.  With the MR definition in place for determining which leg are on you could change it to:

Rule 18 no longer applies between boats when the boat entitled to mark-room has left the mark astern and is on the new leg, or is no longer racing.

I'm not sure why the rule writers favor writing things out like they do.  As a computer programmer, I really like breaking the sentences up into the parts as it is very clear how to parse it.  It is certainly how I write specifications for code.  I think some of it has to do with how the rules get translated into other languages, but I would think it is easier to translate the individual phrases.

I think your change to 'has finished' has problems because you finish as you cross the line, you may still be racing and not clear of the marks. 'Is no longer racing' gets you all of the stuff about being clear of the marks, etc. and matches the time frame that you can be penalized for breaking a rule of Part 2.

Oops!  Sorry - did not mean to change to 'has finished'.

I meant..

So >>>

a) left the mark astern and is on course to begin sailing the next leg
or
b) is no longer racing

<<< works for me.

John,

The Match Racing definition of 'leg' implies the apex of the turn.  However, there is much of the rounding left to go, where a boat may require mark-room.

So while I prefer your more 'quantifiable' moment, I'm not sure that works entirely.  Need to think about that one.

It is true there may be some distance yet to travel to finish rounding the mark once any part of your boat has crossed the line.  But as long as the mark is not clear astern of the boat rule 18 is still in effect and the boat is entitled to mark room (Blue).  What we don't want is a boat to not be entitled to mark room while they still haven't gone around the mark just because the mark is astern, there has to be an additional condition (Yellow).  I think Green is done rounding the mark and rule 18 should be off for her entitlement to mark room.

John,

I do get what you mean.

There are just a couple of issues I have with using 'leg'.

1.  Even the term ' on the new leg' in the JCR18.1(b) still requires some definition to attached to the rule.  It doesn't quite standalone.

2.  The position of the 'leg line' effectively means that the quantifiable moment is dictated only by the mark being astern of the boat.

I'm trying to picture roundings (multiple boats rounding perhaps) where this may not be ideal.  In the attached diagram, should Blue be entitled to mark-room at Pos. 3?


I guess my issue is whether 'mark clear astern only' requires too much precision by the helmsman to establish her rounding while 'overlapped with the mark'.

My Diagram 2 in the first post attempted to illustrate a potential scenario where the boat had cleared the mark, but had not substantially completed her rounding.

Additionally, does the 'leg' definition work when the turn at the mark is not 180 degrees?

Anyway, I'll offer an alternative..

Rule 18 no longer applies between boats when the boat entitled to mark-room has left the mark astern and is either on a course which is less than 90 degrees to the next mark, or is no longer racing.

I think this is standalone without need for further definition, addresses the punctuation/formatting/grammar issue discussed earlier, is quantifiable, and allows for a boat who has not perfectly executed the rounding at the mark some protection to complete that move while she is not yet closing range to the next mark.

Ben -

Point 1 - I don't have a problem with adding a new definition.  It you really wanted to you could incorporate it in the rule but that just makes the rule longer.  Having it as a definition might make rule 23.2 clearer (or not!).

Point 2 - I disagree.  In my diagram the mark is astern of Yellow but she is not on the new leg yet so the 'and' is not true and rule 18 remains in effect.  Also, once a boat is on the next leg, which as you have noted happens earlier, the mark being astern is a very easy thing for the sailors to judge and know that rule 18 is off.  Our last point of certainty concept removes the need for precision.

While we talk about an entitlement to mark room in rule 18, what rule 18 is really about is exoneration for breaking rules.  While you are sailing within the mark room you are entitled to, you have a free pass to break some rules.  So, once the mark is no longer a limitation to your course, the entitlement to room and the exonerations that come with it should end, i.e. rule 18 should no longer apply.

In position 1 all the boats still need room to go around the mark and rule 18 should provide that.  In positions 2 and 3, I would argue that Green has given both Blue and Yellow room to go around the mark and that rule 18 should no longer apply between the various pairs of boats.  The situation should be governed by rules 11, 15, 16, & 17 and not 18.  So Yellow probably should not be exonerated for breaking 11 in position 2 because the mark is no longer a limitation on her course.  In position 3 Blue is breaking 11 and should not be exonerated because the mark is no longer a limitation on her course either.

With your definition, both Yellow in position 2 and Blue in position 3 would still be exonerated for breaking rule 11.  I don't think this is what we want.

I think it does work when the turn at the mark is not 180 degrees.  Suppose it was 90 degrees.  The boats will still cross the leg line at the same time but they will leave the mark astern sooner as they will not be turning as far, but they won't need room as long.

John.

Good discussion.

My point 2 was not so much about your Yellow.  I agree with the mechanism for your Yellow.  I should have been clearer.

It was more to really analyse the situation in my diagram, and ask whether Blue should have continued mark-room, since she was delayed by her obligation to give room to Yellow.

That's exactly the question I'm asking.  If it is truly what we don't want, then the 'new leg' concept works.  However, if a boat should be protected until she has at least turned towards the mark, then 'new leg' doesn't work, and 90 degrees does.

Let's sit on that.

Meantime, looking at JC18.1(b) how about:

Rule 18 no longer applies between boats when the boat entitled to mark-room has left the mark astern and has either crossed the extension of the line from the previous mark through the mark she is rounding, or is no longer racing.

The idea of a new definition of leg will solve countless previous debates on 'what is a leg' for sure.  I'm not sure this working party would want to go into that.

Anyway, good discussion - not sure if anyone else is reading this, but let's rest for a while.