Forum: The Racing Rules of Sailing

The Phrase "changing course substantially" in the Obstruction Definition (and RRS 20.1)

Angelo Guarino
Nationality: United States of America
Certifications:
  • Fleet Measurer
We have US Appeal 15 which provides guidance US Appeal 15 .. and like US15, I'm interested in discussing when it's OK to call for room to tack.

Since we are already non-dimensionalizing the question based upon the length of the boat in question ... it seems to me this comes down to an angle.

What has it been in practice for you in your hearings? 5 deg? 10 deg? 30 deg? more? .. less?

In practice, in an OD fleet in crossing situations to windward, a leeward boat on port with a port boat to windward and on a bow-to-bow collision course with a starboard tack boat, is the course to duck in an OD fleet "substantial"?

What if the course was a mid-boat collision point on the starboard-boat?

I think it's easier to think about this when all the boats are the same size as it takes the boat's dimensions out of it.

Ang

PS .. let's assume the boats are all moving at the same speed for the sake of discussion.
Created: 18-Jun-14 13:30

Comments

Lloyd Causey
Nationality: United States of America
Certifications:
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  • Regional Race Officer
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I don't think that you can define any exact dimension to apply overall nor angle to apply overall. What you are judging is the capability of the leeward boat. An 18 foot one design doing 4 knots can change direction rather quickly, however a 70 foot cruiser doing 7+ knots cannot.

So it is in my opinion that in deciding this call it is all in the ability of the leeward boat since they have the right to decide the side of passing an obstruction. It may be that a tack is required no matter which side the pass is selected. In this case there is only time to reason about details of ability is after the event, because when the leeward boat hails for room to tack, the other must respond.

I think that in a high percentage of times the windward boat that does not respond is going to be DSQ.
Created: 18-Jun-14 14:27
Angelo Guarino
Nationality: United States of America
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Lloyd, I am certainly not suggesting that a boat hailed for "room to tack" has the option to ignore that call .. the rules, cases and appeals are very clear on that. That said, a boat that feels it was not asked for appropriately can protest and there are Cases to support that as well.

I agree that a boat can pass an obstruction to either side, but there are specific limits on when a boat can hail for room to tack to pass it to windward.

The RRS 20.1 repeats Obstruction's "substantial course change" again .. but this time it replaces the 1-boat length with "soon".

So, I would argue that "soon" is further out than the 1 boat-length found in the Obstruction definition, because if it doesn't meet the 1BL test, it's not an obstruction in the first place. So .. now we are maybe 2-3 BL's out and "substantial" is still being applied.

We have the language " .. However, a boat racing is not an obstruction to other boats unless they are required to keep clear of her" in the definition. I think in practice the 'substantial course change' language isn't applied simultaneously with the "keep clear" language and so even if a port tacker could fall off slightly and duck a STB boat, the fact that she had to 'keep clear' of STB is applied as sufficient (though I would argue that how "Obstructions" definition is written, it doesn't specifically state that when "keep clear" applies, "substantial course change" does not) (PS .. I'm interested if the Peanut Gallery agrees with this last statement as well).

So, maybe it's better to replace the STB tack boat with a boat of same size at anchor to remove the "keep clear" aspect for our discussion of "substantial".

Ang
Created: 18-Jun-14 15:35
Paul Hanly
Nationality: Australia
0
In round numbers the beam of a boat is say 1/3 of her length (you could do the math using 1/4 for some narrower boats as an alternative)
If two OD boats are approaching bow to bow and one length apart they will touch bows at half a length.
The port boat must keep clear so let's use 1/2 boat length for distance for beam plus "keep clear" room (assuming flat water and no likelihood of gusts rounding either boat up).
At one boat length apart to move the keel line extensions from the bow apart from in line to half a boat length apart within one boat length my guess is that the course change is about 45 degrees. I don't think there is any doubt that is a substantial change in course by the port tacker. So an oncoming boat is an "obstruction" under the definition.

So as I understand your question we are considering when a hail for room at an obstruction switches from a breach of 20.1 to a legitimate hail.

First I note "1.1 Helping Those in Danger: A boat or competitor shall give all possible help to any person or vessel in danger." A boat on a collision course, or a boat heading at an obstruction will become "in danger" at some point and the other competitor in your example will have an obligation under 1.1 as well as under 19 and 20 (and any other boat on boat rule).

"Soon" and "substantial" in 20.1 are, I believe, not well worded. The timing of the hail in question by the boat headed towards the obstruction is to allow time for all other boats that may have to tack time to pass on hails and respond. I would interpret substantial as the change in course that has to be made to safely pass the obstruction at the time when safety requires a prudent, competent for the type of racing, skipper having regard to the limitations of his boat and crew, to make the change in course - another grey area! "Soon" I would interpret based on all the surrounding circumstances based on giving enough time for the hail (and all further hails) to be effective, including some allowance for time to repeat in the case of hails not being heard and for some margin for time to react. I would not interpret soon based only on some arbitrary time elapse for the boat making the hail. If there is only one boat to windward and you can see the crew preparing for the tack and watching you waiting for the hail, "soon" might not be very long before impact. If it is blowing like stick and the hailing boat reasonably believes there might be 3 or 4 boats stacked up to windward and it can't see how they are set up for a tack and whether or not they are keeping a look out, "soon" would have to be a much longer period of time in the circumstances, otherwise the hail might have to be "help, danger" rather than "room" or "water".

I think the question the protest committee has to answer in relation to a hail is in all the circumstances, was it made so much too soon that it was not a legal hail in the circumstances. I think this is the only way to give effect to the clear intention of the rule and that dwelling too much on the semantics will lead to an unsafe interpretation. That is not to say the wording could not be improved.
Created: 18-Jun-14 22:13
Bill Handley
Nationality: United Kingdom of Great Britain and Northern Ireland
Certifications:
  • National Judge
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I think that it is important not to confuse the use of these words in the definition with the use of them in the rule. The words in the definition are there to define what an obstruction is and in that the use of the word "if" in the second line of the definition is key. For something to be an obstruction a boat does not have to be sailing towards it or have to alter course to avoid it, only if she were doing so (directly towards the centre of it) and had to make an alteration of course at one hull length then the object is by definition an obstruction. Having decided that the object is an obstruction (as it certainly is in this case) you then have to consider the application of rules 19 and 20.

As far as I can see the use of the word soon in rule 20.1 is because the hail has to take place before the need to tack. After the hail there has to be time for the hailed boat to respond and the hailing boat to respond to the response so the hail has to take place some time before the need to tack and the use of the word "soon" seems as good as any to me to describe this situation. The actual duration of the time will be driven by a number of factors - size of boat, wind and sea conditions etc.

RYA Case 1974/1 makes it clear that when P has a choice to bear away or tack to avoid S "no rule requires P to bear away". I interpret this as meaning that if P is on a course to make contact with S by even the slightest degree then she has the choice of tacking or bearing away. If she bears away the course alteration may not be substantial but then she does not require room to tack. If she chooses to tack the the course alteration is substantial (around 90 degrees) and she is entitled to room under rule 20,1.

In summary any time a boat conflicts with an obstruction and can either tack or bear away to avoid it the tack will always be a substantial alteration of course and rule 20.1 will always apply. Any other interpretation leads us down this route of try to decide by degrees and fractions of degrees what is "substantial" and that quite frankly is impossible.
Created: 18-Jun-15 07:41
Angelo Guarino
Nationality: United States of America
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Bill, thanks for the reply but I have a couple issues/questions with what you stated ...

For something to be an obstruction a boat does not have to be sailing towards it or have to alter course to avoid it, only if she were doing so (directly towards the centre of it) and had to make an alteration of course at one hull length then the object is by definition an obstruction.

You didn't insert "substantial" (which is at the heart of my thread). The test isn't simply "had to make an alteration of course" .. it is a "significant" alteration of course. The question at hand is what is "significant"? 5 deg? 10 deg? Certainly we would probably all agree a 30 deg alteration would be significant and likely that a 3 deg alteration is not.

In your RYA Case, I think I'm to the point that in P/S windward situations, the "keep clear" language gives Port the tack/duck choice even if a duck would only take a couple degrees.

That said, let's take the boat at anchor situation, I don't think your summary at the end holds (at least in the US) as Appeal US 15 specifically states (emphasis added)...

"...The police launch was an obstruction since L could not pass it without “changing course substantially” if she were “one of her hull lengths from it.” This, however, did not necessarily give her the right to hail W for room to tack. If she had approached the police launch sufficiently close to its leeward end so that, with only a slight change of course when one of her hull lengths from it, she could have safely passed to leeward of it, she should have done so. "

That said, the first part of US 15's discussion coincides nicely of your description of how to separate the "obstruction" analysis from the application in RRS 20.1.

So Bill, we still have 2 uses of the word "substantial" .. let's assume two overlapped boats on a beat to windward where the leeward boat is approaching a fixed object.

Q1) Is the angle determined "substantial" when determining if the object is an Obstruction the same angle as "substantial" in RRS 20.1?
Q2) Understanding that what "substantial" means is situational to some extent, it seems to me that common experience would allow us to bound both ends to a 90th percentile standard ... i.e. certainly a 25 degree course change will nearly always be "substantial" and a 5 deg course change will almost always not be?

Ang

PS .. actually rereading the US15 language, they are placing the boat situationally 1 BL away at the leeward end (not at the center as you did non-situationally) .. so US15 doesn't really jive with your separate approach.

Created: 18-Jun-15 12:26
Bill Handley
Nationality: United Kingdom of Great Britain and Northern Ireland
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Ang - I'm sorry if didn't make myself clear - my intention was not to agree with the conclusions of USA 15 but to disagree with it at least in part.

As far as the definition goes I think it is clear. As I said before the use of the word if invites us to create a hypothetical situation of a boat sailing directly towards the mark at one boat length. If her alteration of course to avoid it impacts on another boat which is then required to give room or room to tack then it is substantial because it of substance to the boat with the obligation.

The use of the word substantially in the definition simply means that the change of course must be of substance and this is self proving. The presence of an obstruction is of relevance in so much as it may trigger the right to room under rule 19 or room to tack under rule 20. If even a slight change of course requires the boat obliged to give room to change course herself this is of substance. For example if two boats overlapped on the same tack were passing to leeward of a moored boat and W had to make even the slightest alteration of course to bear away it is of substance to L because she must bear away and give W room.

Turning to the question of two boats approaching a moored boat with L only having to make a slight alteration of course to avoid by bearing away I think RYA 1974/1 remains good and the statement that there is no rule that requires L to bear away is just as applicable.. In that circumstance L may either tack or bear away at her own choice and if she chooses to tack that is a substantial alteration of course which triggers rule 20.1. It is in this area that I see a conflict between USA 15 and RYA 1974/1 and as these are both national decisions and therefore only advisory we will just have to agree to operate under different regimes.

If your logic were to be accepted then a boat approaching a moored boat with boats to windward and leeward of her and only needing to bear away 5 degrees to pass to leeward of the moored boat would be in an impossible position. She could not hail for room to tack or for room to pass the obstruction because her change of course to pass was not substantial.
Created: 18-Jun-15 15:11
Angelo Guarino
Nationality: United States of America
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Bill,

If your logic were to be accepted then a boat approaching a moored boat with boats to windward and leeward of her and only needing to bear away 5 degrees to pass to leeward of the moored boat would be in an impossible position. She could not hail for room to tack or for room to pass the obstruction because her change of course to pass was not substantial. ...

... my intention was not to agree with the conclusions of USA 15 but to disagree with it at least in part.

Seems that's precisely what US15's discussion describes. It's survived on the US Appeals Book since 1959.

I think we can go back to your splitting of the "significant course change" measures .. one at 1BL centered on the object in the Obstruction definition and one "situationally" with the "soon" spacing and make US15 work, if we forget that they reused the 1BL measure when applying RRS20.1 at the leeward end (being that the appeal is so old, maybe the language missed an update?).

If we do that ... then the police boat in US15 is an Obstruction based upon the centered-1BL test and thus the middle boat (in your scenario) has the right to pass to either side .. and thus rights to room from the boat(s) to leeward allowing to pass the moored-boat to leeward .. but at the same time if its only 5 deg course change, she doesn't have the right to call for room to tack.

Ang

Created: 18-Jun-15 15:33
Bill Handley
Nationality: United Kingdom of Great Britain and Northern Ireland
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Ang - I think we have to agree to disagree on this although I think we are now in agreement that the police boat is an obstruction according to the definition no matter how a boat is approaching it.

If L were approaching very near the leeward end of the police boat it would still be an obstruction according to the definition. RRS 19.2(a) makes it clear that a r-o-w boat (L in this case either under rule 11 or 12) may choose to pass the obstruction on either side. This has to mean that she can either bear away and leave it to starboard or tack and leave it to port. If she chooses to tack then she will turn through around 90 degrees which is a substantial alteration of course and rule 20.1 applies.

I'm afraid I can't see it any differently from that. The wording of 20.1 changed in the last lot of rule changes and although the changes were quite subtle I think that the old words may have supported the view of US15 whilst the new words do not.
Created: 18-Jun-15 15:50
Paul Hanly
Nationality: Australia
0
Ang, if you do the math as outlined in my post above I expect you will see that there is no doubt that any boat will meet the definition of an obstruction, even when approaching directly bow to bow. I agree with Bill that you may have overlooked the "if" in the definition.

In RRS 20 I think the issue is "soon", not "substantial". At some point of time approaching a boat, even bow to bow, there will arise a need to make a "substantial" change. I estimated 45 degs at one boat length. The question is then when does "soon" begin. No one would doubt that it starts before one boat length. "Soon" has to be evaluated in the circumstances or the rule fails to fulfil its clear intention of allowing a boat to avoid obstructions, particularly when you consider RRS 20.3 exists. You can't sensibly interpret "soon" to exclude the effective operation of RRS 20.3.

I agree with Bill as to the factors he mentioned in determining " soon" but would add that the number of boats reasonably thought to be stacked to windward and how long the 20.3 process can be thought likely to take in the circumstances also has to be allowed for.

As a skipper of a boat beating to windward with 6 crew hanging over the rail and bow on with another boat that you had to keep clear of, with 4 x 5 ton boats stacked to windward of you in a 2 metre swell, blowing 25 knots in rain, when would you start to worry that you have to make your substantial change in course "soon"?
Created: 18-Jun-15 15:51
Angelo Guarino
Nationality: United States of America
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  • Fleet Measurer
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Paul, I think all your questions are good ones (and the reason I started the thread .. to get some thoughts on it) ... except in your first reply, the idea that a boat under control, integral, no crew injuries, nobody over-board would trigger an RRS 1.1 is outside of its intention IMO.

I'm not a fan of words that have no meaning as they are useless. If "substantial" means any discernible course change, then it really doesn't qualify "course change" in any meaningful way.

I'm not an RRS historian, but it seems "substantial" has been with us since at least the 1950's ... so it must mean something.

Somehow it must limit a boat's ability to hail for room to tack to avoid an obstruction .. but it seems we are struggling to find a time when it would.

Ang

PS .. of course the RRS's are happy to live with the simple concept of "changing course" as we have the plain language of RRS 16.1. Therefore I would argue that the substantial course-change described in Obstruction and 20.1 must mean something larger than the 'discernible' course-change in 16.1.
Created: 18-Jun-15 16:39
Paul Hanly
Nationality: Australia
0
Thanks Ang,

After writing a much longer response I came to the conclusion that we are at cross purposes.

If the leeward boat can pass the obstruction safely while close hauled then to hail would be unsporting and illegal.

If you are talking only about the very limited case where a 1 deg change in course above close hauled say two boat lengths away will take the leeward boat safely past the obstruction then I guess it is not a substantial change in course that is required, so I can see that you would argue that no right to hail arises.

And if it is only 3 degrees change say 2 boat lengths away to pass safely, then maybe no right to hail arises.

Clearly a 30 degree change 2 boat lengths away is substantial.

I am going to say any more than 5 degrees above close hauled 2 boat lengths away is substantial,

But then the problem is whether 4 boats stacked up to windward could ever be hailed in time.

But what if there is a gust approaching that looks like a knock not a lift?

You have to look at all the surrounding circumstances, even in the very limited case to which I now think/understand you are referring .

I cant describe it in advance, but I'll know it when I see it described in the protest room! (wink)
Created: 18-Jun-15 18:40
Grant Baldwin
Nationality: United States of America
Certifications:
  • International Judge
  • National Umpire
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OK boys, I cannot help myself here. I think that these discussions are best helped by getting them wet.

Angelo's original post focused on the problem of the obstruction presented a keep clear boat by a right-of-way boat, so let's get in our little boats. Angelo is on starboard tack and I am on port tack. In order to avoid him, I have to crack off slightly to clear his stern (sure, I could have tacked, but I wanted the right side anyway). Was this minor alteration "significant"? I (as a competitor) would argue that it was, because I lost a little gauge on my competition and I never wish to willingly give that up. Put another port tacker on my hip and this becomes a "no brainer", but in a hearing, I always give some latitude in the judgement of the boat entitled to room.

The same is true in incidents where a "premature hail" is alleged. Here in San Francisco, we often hit a continuing obstruction on a beat and it is not uncommon to have 2-3 boats stacked up on your hip when calling for room at the rocks. If you think I'm calling for "water" too early, your defense is to respond "you tack" to flip the obligation. Again, RRS 20 is a safety rule and works well when carefully observed.

As a mentor of mine taught me, hydrate the situations that come before you. As a judge or umpire, don't forget to think like the sailor you are. The RRS are an imperfect and evolving work and as officials, its easy for us to get caught up in parsing language. The word "significant" in this application means to be "worthy of note". My little duck to avoid Angelo was "noteworthy" because it was measurable and I had to work to make up the distance that cost me.

Peace,

GB
Created: 18-Jun-15 18:44
Lloyd Causey
Nationality: United States of America
Certifications:
  • Regional Judge
  • Regional Race Officer
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Grant,
I like your wisdom. I do believe that these discussions often go into "parsing the language" with factors not even mentioned in original post. It is really difficult to dissect a hypothetical incident. You never have all the details and it is hard to cover all of those "what ifs".
Created: 18-Jun-15 18:55
Angelo Guarino
Nationality: United States of America
Certifications:
  • Fleet Measurer
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Grant ... thanks for jumping in ...

the word "significant" in this application means to be "worthy of note". My little duck to avoid Angelo was "noteworthy" because it was measurable and I had to work to make up the distance that cost me.

So, like I said in my last post ... if any measurable course-change is "significant" then all course changes are "significant" (as why discuss imperceptible course changes) and the modifier "significant" has no meaning. On the other hand the RRS's uses it 2x in 20.1 and in the Def's.

In the US, we also have US Appeal 15's very plain and clear description (which I started the thread referencing) which describes a situation where the right to call for room to tack is potentially limited upon the modifier "significant" ..

This, however, did not necessarily give her the right to hail W for room to tack. If she had approached the police launch sufficiently close to its leeward end so that, with only a slight change of course when one of her hull lengths from it, she could have safely passed to leeward of it, she should have done so. "

I'm still looking for someone in the US .... (seems our British and Aussie pals have an out) .. to square US 15. It's an Appeal (thus not definitive) so maybe the consensus of the US Judges here on this forum is that they choose not to follow its guidance in practice?

Ang

Created: 18-Jun-15 21:11
Paul Hanly
Nationality: Australia
0
So Ang, now that we have dealt with the leeward end of an obstruction able to be passed on both sides and passed to leeward by a few degrees change in course, what about:
a) the windward end of a similar obstruction
b) an obstruction that is only able to be passed to windward by sailing above close hauled but which a competitor could have pinched past
c) like b) except the competitor could have got past by shooting towards head to wind say 3/4 of a boat length away
d) an obstruction that can not be passed as in b) or c) but where there are say 4 boats stacked to windward in a gusty 17 knot breeze and a 1/2 metre chop (common in Sydney on a summer afternoon or twilight). - How do you interpret "soon"?
Created: 18-Jun-16 03:17
Angelo Guarino
Nationality: United States of America
Certifications:
  • Fleet Measurer
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Paul, sorry for the delayed response .. busy Father's Day with BBQ'ing and fixing my daughter's refrigerator (always a good day in my book when I get to grill and get my toolbox out while looking at schematics!).

a) the windward end of a similar obstruction

If US 15 is applied, I would think the same "substantially" measure would need be applied.

b) an obstruction that is only able to be passed to windward by sailing above close hauled but which a competitor could have pinched past

See above, without further guidance IMO as long as their sails were still full (pinching but not luffing) that a room to tack call could be questioned. Again, questioning the call for "room-to-tack" SHOULD NOT be confused with not honoring the call on the water. The Rules and Cases are clear that a boat that is called-upon for "room to tack" has to respond by tacking or replying "you tack". There is no arguing about it on the water, but rather if the boat called-upon disagrees with the request .. they can protest and make the case later that the call was inappropriate.

c) like b) except the competitor could have got past by shooting towards head to wind say 3/4 of a boat length away

See above, shooting an obstruction IMO is not only substantial, but also potentially dangerous and certainly if that was required, they have the right to call for room to tack.

d) an obstruction that can not be passed as in b) or c) but where there are say 4 boats stacked to windward in a gusty 17 knot breeze and a 1/2 metre chop (common in Sydney on a summer afternoon or

If the obstruction can't be passed as in (b) or (c), IMO they have the right to call for room to tack. Though the boats to windward do not need to respond until they hear the hails, that does not absolved them of situational awareness. They are windward boats on the same tack with one boat at least approaching an obstruction .. IMO they need to be on alert for being luffed up to provide room for boats to pass to windward of the obstruction as well a potential call for room to tack from the most leeward boats. Just like when on a port-windward beat, you need to be aware for boats on STB .. or overlapped and windward at the starting line, you need to be looking for the boat to leeward to head you up .. when approaching an obstruction or potential obstruction as the windward boat, you should be prepared.

Happy Father's Day!

Ang

Created: 18-Jun-18 16:09
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