Forum: The Racing Rules of Sailing

Transitions

P
John Allan
Nationality: Australia
Certifications:
  • National Judge
  • Regional Race Officer
Umpires and judges often talk about ‘transitions’, and the concept is a very useful tool in analysing and resolving When Boats Meet rules problems.

Remarkably the term is not discussed in either the Judges or Umpires Manuals.

I have prepared a paper to

●       explain what transitions are,
●       give some examples of sequences of transitions, and
●       show how transitions are used to analyse a typical rules problem.

The paper says the following


A transition is an event when rules, usually the Part 2 When Boats Meet rules, applicable between boats changes.  Transitions can be either:

●       ‘Rules only’ transitions, where the applicable rules change, but the obligations or entitlements of boats do not;  or
●       Transitions where obligations or entitlements, as well as applicable rules change. 

Obligation or entitlement transitions may be further subdivided into:

●       Right-of-way transitions (RRS 10, 11, 12, 13, and 21);  and
●       Room transitions (RRS 15, 16, 18, 19 and 20);  and
●       Other transitions (RRS 17 Proper Course, RRS 22 Capsized, Anchored or Aground; Rescuing, and RRS 23 Interfering with Another Boat).

The paper then provides 7 examples of transitions, each of which I will post separately.

I'd appreciate any comments or feedback on the above, and then on the examples as I post them.

I'll post the final paper here when I finish it.

EDIT:  Here's the final document


Transitions.docx 397 KB
Created: 24-Feb-21 01:14

Comments

P
John Allan
Nationality: Australia
Certifications:
  • National Judge
  • Regional Race Officer
1

  1. Example 

A simple example of a transition is when one of two boats, initially overlapped on starboard tack passes head to wind.

Consider Figure 1

Figure 1

Initially (Y)ellow is required by RRS 11 On the same tack overlapped, to keep clear of (B)lue.

@3, when Y passes head to wind, RRS 11 no longer applies and RRS 13 While tacking begins to apply, so that Y is now required to keep clear of B.

This is a right of way transition.
Created: 24-Feb-21 02:05
P
John Mooney
Certifications:
  • National Judge
  • Regional Race Officer
0
I'm looking forward to this paper! I agree the concept is inadequately explained in most of our training materials.
Created: 24-Feb-22 02:46
P
John Allan
Nationality: Australia
Certifications:
  • National Judge
  • Regional Race Officer
0
 1.     Example 

A simple example of a transition is when two boats, (B)lue and (Y)elow are sailing downwind, overlapped on starboard tack, with Y sailing faster than B. 

Consider Figure 1 

Figure 1 

@1, Y overlapped to windward on the same tack is required to keep clear of B by RRS 11 On the same tack, overlapped. 

@2, Y draws clear ahead of B and B, clear astern on the same tack, is now required to keep clear of Y by RRS 12 On the same tack not overlapped. 

This is a right-of-way transition. 

Created: 24-Feb-22 21:56
Richard Jones
Nationality: United Kingdom
0
Hi John, that would be very useful

I think in your  No 1 example you say:-  "Initially (Y)ellow is required by RRS 11 On the same tack overlapped, to keep clear of (B)lue.

I think its Blue must keep clear as windward boat.

Yellow doesn't lose ROW until she passes HTW to port.

Created: 24-Feb-23 19:25
P
John Allan
Nationality: Australia
Certifications:
  • National Judge
  • Regional Race Officer
0
Thank you Richard.  Good get.  Draft corrected.

Here are some more examples

 

2.     Example 

Continuing on from the previous example, Y gybes from starboard onto port tack. 

Consider Figure 2

image.png 30.3 KB

 
Figure 2 

@ 3, Y, still clear ahead of B, but now on port tack, is required to keep clear of B on starboard tack by RRS 10 On opposite tacks. 

This, again, is a right-of-way transition. 

@4, Y and B are once again overlapped, but there is no change in right-of-way, room, or rules applicable. 


2.     Example 

Here is an example of a room transition with no change in right-of-way.  B and Y are sailing on port tack, downwind to a mark to be rounded to port. 

Consider Figure 3 

Figure 3 

@1, B is overlapped to windward on the same tack as Y, and required by RRS 11 On the same tack overlapped to keep clear of Y. 

@2, Y reaches the zone around the mark, overlapped outside B.  RRS 18 Mark-room begins to apply, and Y is required to give B mark-room by the first sentence of RRS 18.2(b) Giving mark-room. 

There is no change in right-of-way, but if B, while sailing within the mark-room to which she is now entitled, does not keep clear of Y, she is exonerated by RRS 43.1(b). 

This is a room transition. 

Created: 24-Feb-23 19:54
P
John Allan
Nationality: Australia
Certifications:
  • National Judge
  • Regional Race Officer
0

More Complicated Examples


1.     Example

Here is a more complicated example involving both right-of-way and room transitions.

B and Y are sailing downwind, initially overlapped both on port tack.

Consider Figure 4

Figure 4

@1, B, overlapped to windward on the same tack, is required to keep clear of Y by RRS 11 On the same tack, overlapped.

@2, B gybes onto starboard without changing course.  Y, on port is required to keep clear of B on starboard by RRS 10 On opposite tacks

This is a right-of-way transition.

@2 also, B, acquiring right-of-way not because of Y’s actions is initially required to give Y room to keep clear by RRS 15 Acquiring right-of-way.

This is a room transition.

@3, B changes course away from Y and gives Y room to keep clear.

Created: 24-Feb-24 13:40
P
Angelo Guarino
Nationality: United States
Certifications:
  • Regional Judge
  • Fleet Measurer
0
John … cool stuff. I’d like to make a stylistic suggestion for those of us who get easily confused. :-)

In the finished document, when all these examples are flowing one after the other, instead of labeling/referring to the figures as “figure 1” “figure 2” but the examples starting over in numbering by category … increment the examples and figures in-sync such that Example 1 has Figure1 . Example 8 has Figure 8... and if you need more than 1 figure per example do a 1A, 1B .., etc. 

For some reason my brain locks-up when I see Example 1 figure 4. 
Created: 24-Feb-24 15:15
P
John Allan
Nationality: Australia
Certifications:
  • National Judge
  • Regional Race Officer
0
Thanks Ang,  The document is set up to do that, it's just that when I copy a bit across, the # Example heading renumbers itself to 1. Example when pasted into RRS.org.
Created: 24-Feb-24 20:58
P
John Allan
Nationality: Australia
Certifications:
  • National Judge
  • Regional Race Officer
0
 5.     Example 

Another example is when one of two boats, initially overlapped on starboard tack luffs and passes head to wind. 

Consider Figure 5
image.png 19.5 KB



Figure 5 

Initially B is required by RRS 11 On the same tack overlapped, to keep clear of Y. 

@2 when Y begins changing course she is required by RRS 16.1 Changing Course to give B room to keep clear, and given the distance apart of the boats, she does so. 

This is a room transition. 

@3, when Y passes head to wind, RRS 11 no longer applies and RRS 13 While tacking begins to apply, so that Y is now required to keep clear of B. 

This is a right of way transition. 


6.     Example 

Continuing on from that, Y continues to bear away and @4 reaches her close hauled course on port tack. 

Consider Figure 6. 

Figure 6 

Now there is a further transition @4 when Y reaches her close hauled course, RRS 13 no longer applies, Y is now on port tack and still required to keep clear of B, but the obligation now arises under RRS 10 On opposite tacks.  SL’s obligation to keep clear has not changed. 

This is a rules only transition. 

Created: 24-Feb-25 06:41
P
Angelo Guarino
Nationality: United States
Certifications:
  • Regional Judge
  • Fleet Measurer
0
John re #5 and rule 16

@2 when Y begins changing course she is required by RRS 16.1 Changing Course to give B room to keep clear, and given the distance apart of the boats, she does so.

Only pointing out “begins changing course” may leave the wrong impression.  Maybe rephrase it as to point out that 16.1 room requirement “resets” (or some other term .. maybe is “continuously recalculated”) each moment Y continues to alter course between 2 and 3 where her room obligation ends when Y is no longer right of way, though Y continues to change course (simultaneous ROW/room transition @3). 
Created: 24-Feb-25 13:07
P
John Allan
Nationality: Australia
Certifications:
  • National Judge
  • Regional Race Officer
0
Thanks Angelo, I'll have a good think about that.

Here's the next example.

7.     Example 

Here is a more complicated example involving both right-of-way and several room transitions. 

B and Y are sailing downwind approaching an obstruction. 

Consider Figure 7 

Figure 7 

@1 B, initially on the same tack, clear astern, is required to keep clear of Y by RRS 12 On the same tack not overlapped. 

@2, B becomes overlapped to leeward of Y: 

·        B acquires right of way, and Y, to windward on the same tack, is required to keep clear of B by RRS 11 On the same tack, overlapped. 
This is a right-of-way transition. 
·        B, acquiring right-of-way not because of Y’s action, is required by RRS 15 Acquiring right-of-way, initially, to give Y room to keep clear, which she does and then RRS 15 ceases to apply. 
These are room transitions. 
·        Boats are at the obstruction indicated by the wiggly line, so, now they are overlapped, RRS 19 Giving room at an obstruction requires B to give Y room to pass between her and the obstruction. 
This is a room transition. 

Between @3 and @4 B bears away and gives Y room to pass the obstruction. 

Created: 24-Feb-26 20:01
P
John Allan
Nationality: Australia
Certifications:
  • National Judge
  • Regional Race Officer
0
 8.     Example 

A more complicated example of transitions, involving right-of-way, room, and rules only transitions, happens with two boats reaching, both on starboard tack initially with Y clear ahead of B when B becomes overlapped to leeward of Y. 

 
Consider Figure 8 

Figure 8 

@1, B, clear astern, is required by RRS 12 On the same tack, not overlapped to keep clear of Y, on the same tack. 

@2, B becomes overlapped to leeward of Y on the same tack, and: 

  • Y is required to keep clear of B by RRS 11 On the same tack, overlapped, 
This is a right-of-way transition. 
  • B, acquiring right of way not because of Y’s action is required initially to give Y room to keep clear by RRS 15 Acquiring right-of-way.
This is a room transition 
  • B, becoming overlapped within two of her hull lengths to leeward of Y on the same tack is required to not sail above her proper course by RRS 17 On the same tack Proper Course. 
This is a transition, other than right-of-way or room. 

@3, B has borne away and given Y room to keep clear. 

B’s course after becoming overlapped was consistent with her course before becoming overlapped and with Y’s course:  there is no evidence that she is sailing above her proper course. 

@4, B has drawn clear ahead of Y, RRS 11 On the same tack, overlapped no longer applies, but B remains the right-of-way boat because Y is now required to keep clear by RRS 12 On the same tack, not overlapped. 

This is a rules only transition. 

@4, B is no longer overlapped on Y, RRS 17 On the same tack Proper Course ceases to apply and B is no longer required to not sail above her proper course. 

This is a transition when RRS 17, a limitation other than right-of-way or room ceases to apply. 

@4 B, now clear ahead and not limited by RRS 17, changes course to windward.  B, a right of way boat is changing courses and is required by RRS 16.1 Changing course to give Y room to keep clear, and does so. 

This is a room transition 
Created: 24-Feb-27 20:36
P
John Allan
Nationality: Australia
Certifications:
  • National Judge
  • Regional Race Officer
0
Big example for comment: Using Transitions
 
Here is a worked example of using transitions to analyse a rules problem to identify: 

·        what rules were applicable, and 
·        whether any rules were broken 

(R)ed and (G)reen are sailing on a beat to windward as shown in Figure 9. 

Figure 9 


Analysis

@1, both boats are on port tack, R is clear astern of G, and is required to keep clear of G by RRS 12 On the same tack, not overlapped. 

@1.5, as G changes course to windward: 

·         G becomes overlapped to leeward of R and R continues to be required to keep clear of G, but now under RRS 11 On the same tack, overlapped;  and 

·        G, a right-of-way boat changing course is required to give R room to keep clear by RRS 16.1 Changing course, and does so. 

@2, G passes head to wind and is required to keep clear of R by RRS 13 While tacking. 

@3, G reaches her close hauled course on starboard tack: 

·        R is required to keep clear of her by RRS 10 On Opposite tacks;  and 

·        G, acquiring right-of-way not because of any action of R, is required initially to give R room to keep clear by RRS 15 Acquiring right-of-way. 

@3+delta: 

·        R, acting promptly after becoming required to keep clear, begins changing course to windward in order to keep clear as required by RRS 10, On Opposite tacks. 

·        G changes course to windward in order to give R room to keep clear as required by RRS 15 Acquiring right-of-way. 

·        R and G are on a collision course so close together that there is a reasonable apprehension that if G does not change course there will be contact so R is not keeping clear of G and R breaks RRS 10 On opposite tacks. 

·        R is sailing within the room to which she is entitled and is exonerated for breaking RRS 10 by RRS 43.1(b) Exoneration. 

·        G is giving R room to keep clear, and is complying with RRS 15 Acquiring right-of-way. 

@4, R passes head to wind and is now required to keep clear by RRS 13 While tacking, and G continues to give R room to keep clear. 

@4.5, R has borne away onto a divergent course from G, there is enough space between R and G for G to change course in either direction without immediately making contact with R and R is keeping clear of G. 

@5, R reaches her close hauled course on starboard tack, overlapped to leeward of G: 

·        G is required to keep clear of R by RRS 11 On the same tack overlapped, and 

·        R is required initially to give G room to keep clear by RRS 15 Acquiring right-of-way 

Both boats comply with these rules 

@5+delta R has given G room to keep clear and G has kept clear and RRS 15 Acquiring right-of-way no longer applies. 

@6 G bears away onto her close hauled course and continues to keep clear of R. 


Rules Applicable 

@1 

·        RRS 12 On the same tack, not overlapped 

Between @1 and @2 

·        RRS 11 On the same tack, overlapped (rules only transition) 
·        RRS 16.1 Changing course 

Between @2 and @3 

·        RRS 13 While tacking 
·        RRS 10 On Opposite tacks 
·        RRS 15 Acquiring right-of-way 

Between @3 and @4 

·        RRS 10 On Opposite tacks 
·        RRS 15 Acquiring right-of-way 
·        RRS 43.1(b) Exoneration 

Between @4 and @5 

·        RRS 13 While tacking 

Between @5 and @6 

·        RRS 11 On the same tack overlapped 
·        RRS 15 Acquiring right-of-way 


Rules broken

Throughout the various changes in right-of-way and obligation to give room to keep clear no boat broke a rule. 
Created: 24-Feb-29 20:01
P
John Allan
Nationality: Australia
Certifications:
  • National Judge
  • Regional Race Officer
0
 Angelo Guarino Said John re #5 and rule 16 Created: 24-Feb-25 13:07 

@2 when Y begins changing course she is required by RRS 16.1 Changing Course to give B room to keep clear, and given the distance apart of the boats, she does so.

Only pointing out “begins changing course” may leave the wrong impression.  Maybe rephrase it as to point out that 16.1 room requirement “resets” (or some other term .. maybe is “continuously recalculated”) each moment Y continues to alter course between 2 and 3 where her room obligation ends when Y is no longer right of way, though Y continues to change course (simultaneous ROW/room transition @3). 

Thank you Angelo.

Fixed.  Now reads

 
@2 Y begins changing course.  While she changing course she is required by RRS 16.1 Changing Course to give B room to keep clear, and given the distance apart of the boats, she does so. 
Created: 24-Mar-07 21:31
P
John Allan
Nationality: Australia
Certifications:
  • National Judge
  • Regional Race Officer
1
Here's the final document

Transitions.docx 397 KB
Created: 24-Mar-07 21:33
Bob Lewis
Nationality: Canada
0
John when you said “While she changing course she is required by RRS 16.1 Changing Course to give B room to keep clear, and given the distance apart of the boats, she does so. ” did you mean to say “is changing course”.  I also think that using the phrase “while she is changing course” makes it sound like 16.1 turns off when the course changing stops.  The English is a bit difficult. :-) 
Created: 24-Mar-14 05:40
P
John Allan
Nationality: Australia
Certifications:
  • National Judge
  • Regional Race Officer
0
Thanks Bob for correcting the typo.

Angelo raised a similar point, but I wanted to keep the example simple.  I guess I'll have to add another sentence.
Created: 24-Mar-14 11:51
P
John Allan
Nationality: Australia
Certifications:
  • National Judge
  • Regional Race Officer
0
Bob, Angelo, here's a further attempt at Example 5

 
Consider Figure 5
image.png 19.5 KB
 
Figure 5 

Initially B is required by RRS 11 On the same tack overlapped, to keep clear of Y. 

@2 Y begins changing course.  From that time she is required by RRS 16.1 Changing Course to give B room to keep clear, and given the distance apart of the boats, she does so. 

This is a room transition. 

Created: 24-Mar-14 20:19
Bob Lewis
Nationality: Canada
0
Thanks John, I think your new version reads OK and is better.

What I was thinking was something like this:

@2 Y changes course in an arc up to head to wind.  At each point in the arc there is an additional course change and a new instance of 16.1 is invoked. For each of these course changes she is required by RRS 16.1 Changing Course to give B room to keep clear, and given the distance apart of the boats, she does so.

Is this an instance transition?:-)

Created: 24-Mar-14 21:46
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