Which colregs should we ignore?

[timbartlett]

As far as I am concerned, at 3 miles(ish) separation in a small motor vessel, Colregs has not even come into play. I simply take action that I know with absolute certainty, will remove any potential collision risk.

If you cannot identify whether a collision risk exists or not, I really don't see how you can say that turning one way or the other will guarantee to prevent it.

If you choose to take action which is expressly prohibited by the two distinct paragraphs of the colregs (17a and 17c), and by a legal precedent (Banshee-Kildare) that has stood for over a century, that is your prerogative and your responsibility. It is not up to me to endorse your action, and no matter how much you and I may argue it will make no difference to what the colregs say.

I'm genuinely sorry if that sounds "pompous", but it sounds as though you are blaming me either for writing the rules or for a high court judgement that was made when my grandfather was a babe in arms!

AFAIK the only official proposal on this subject would have had the opposite effect to the one you want, by removing the 6 mile limit set by the Banshee-Kildare judgement. IMO rejected that particular proposal, but it could be a sign of the way things are heading.

 

[Observer]

BB,

First, let's assume that radar's not available. Most pleasure vessels don't have it and there's several good reasons it may not be in use anyway. So assume, if you will, that you (or I) are relying on Mk I eyeball.

Second, there are plenty of valid reasons (I shouldn't need to give them but I will if you feel it necessary) why a first assessment of collision risk may be made (or completed) at a separation of ~3 miles.

Third, I think you're looking at this from the perspective of a sailing vessel. That's understandable but it's not the illustration I posed in my question. It makes a huge difference. To illustrate - taking the ~1 mile separation I specified (let's assume that a ship is on 090° and west of your extended track by 1 mile at a speed of 15kts), a collision situation would put you (as a sailing vessel at 5kts on a course of 000°) 1/3 mile south of the ship's extended track. Bearing in mind I specified that it seemed likely I would just pass ahead, the actual distance south of the ship's track may be half that, 1/3 mile, which would give a CPA of ~1/3 mile. I would agree, in that situation, that you would (should) already have taken action.

By comparison, as the skipper of a power vessel, using the same ~1 mile separation and assuming that both my vessel and the ship are at 15kts, that would put the ship 1 mile west of my extended track and me 1 mile south of the ship's extended track. That is a comfortable distance, at that speed, to set as a final decision point. I still have ~4 minutes to take avoiding action if necessary.

Fourth, you, in your sailing vessel, may well find it appropriate to wield a hand bearing compass at every vessel that hoves into view. At 15kts (or more) that's simply not necessary, advisable or practicable. You form an initial assesmment by eye (reference windscreen pillar or similar) and then fine-tune, if necessary, by using more exact aids. So my hypothesis of a 'I could be passing ahead' at 3 miles and then 'I think I will be passing ahead but the CPA looks uncomfortably tight' at 1 mile is a very realistic and plausible illustration of a dilemma that a skipper may actually face. I note that it did not elicit a direct response from either you or Tim Bartlett.

Thanks for the book recommendation. I trust that it is more pertinent to the ship/small vessel situtaion than Tim's "Cockroft & Lameijer".

 

[Observer]

If you cannot identify whether a collision risk exists or not, I really don't see how you can say that turning one way or the other will guarantee to prevent it.

That's the problem. You are confusing the "collision risk" conditions, as defined in Colregs, with actual collision risk. I can be absolutely certain, with 30kts speed available and a turning circle of 50m compared to 1000m (200m ship using your turning circle estimates), that I will never be at risk (barring sudden engine failure, which can be seen as sufficiently unlikely to be discounted) of actually colliding with a ship, subject only to the assumptions that I am giving a reasonable amount of attention to the job and not behaving like a total moron. (If I am a sailing vessel, the risks are obviously different.)

If you choose to take action which is expressly prohibited by the two distinct paragraphs of the colregs (17a and 17c), and by a legal precedent (Banshee-Kildare) that has stood for over a century, that is your prerogative and your responsibility. It is not up to me to endorse your action, and no matter how much you and I may argue it will make no difference to what the colregs say.

I thought we were having a discussion. I'm certainly not looking for your endorsement - just challenging your opinions.

I'm genuinely sorry if that sounds "pompous", but it sounds as though you are blaming me either for writing the rules or for a high court judgement that was made when my grandfather was a babe in arms!

I would certainly not accuse you of being "pompous". Perhaps "blinkered". The position you are occupying appears to be "the law is the law", which I would expect from a law enforcement officer or someone in a regulatory role, but not from a free-thinker.

 

[timbartlett]

I can be absolutely certain, with 30kts speed available and a turning circle of 50m compared to 1000m (200m ship using your turning circle estimates), that I will never be at risk (barring sudden engine failure, which can be seen as sufficiently unlikely to be discounted) of actually colliding with a ship

If that is the case, then why are you so keen to alter course at three miles? Why not let it go for another mile or so, by which time the ship will probably have altered course. If it hasn't, you will have had another mile in which to decide what is really happenning, and you will still have plenty of room left to make what will then be a perfectly legitimate manoeuvre.

I thought we were having a discussion. I'm certainly not looking for your endorsement - just challenging your opinions.

I thought that, too. But whilst we can discuss opinions, there is nothing to be gained by discussing facts: it just becomes boring. And the fundamental fact is the text of Rule 17. We can't change that.

The position you are occupying appears to be "the law is the law", which I would expect from a law enforcement officer or someone in a regulatory role, but not from a free-thinker.

I accept that criticism up to a point.
I have nothing but contempt for our corrupt and incompetent civil service and for its puppets in so-called government, and I despise those in authority who abuse the law for their own ends. But I have enormous respect for the law in general, and particularly for "good" laws, which have a worthy objective and a reasonable track record of success.

I agree that Rule 17 is not one of the best bits of the colregs, and if I ruled the world, I would probably start rewriting it from a blank screen. But it exists, and even if you or I choose to ignore it, the chances are that others will not be ignoring it, and will not be expecting us to do so. So the practical problem is not "What would we like Rule 17 to be?" or "What would I do if it didn't exist?" but what is the most practical way to deal with a situation, whilst applying Rule 17 as it exists.

If we're going for a hypothetical re-write, that's a different matter entirely, but I think we'd need to look at the colregs as a whole, not a rule-by-rule tweak. And I'd be wary of doing it on a website, in case someone mistook our rules for the real ones!

 

[toad_oftoadhall]

But it exists, and even if you or I choose to ignore it, the chances are that others will not be ignoring it, and will not be expecting us to do so. So the practical problem is not "What would we like Rule 17 to be?" or "What would I do if it didn't exist?" but what is the most practical way to deal with a situation, whilst applying Rule 17 as it exists.

Firstly, rule 17 is so vague as to be impossible to judge if any two boats are ignoring it or not. Indeed the people who ignore it seem to be behaving more predictably than those who don't who can't even agree what it requires! Certainly it doesn't achieve what it intends to do.

However it seems pretty clear to me that re-writing rule 17 properly is impossible for exactly the same reason that it needed to be written so poorly in the first place. A rule forcing vessels to stand on to the bitter end be madness. A rule that allowed people to take avoiding action whenever they felt prudent would also end in chaos and collisions. Which is why I guess they chose the word 'apparent' in the first place which doesn't exclude either action or allow either action. It can be argued either way.

 

[snowleopard]

I'd like to address an issue that is often skimmed over in the discussion of collision courses, i.e. how reliable are your compass bearings? Bear in mind that these situations tend to happen in open sea where a small boat is bouncing about and even the best-damped hand-bearing compass card is wandering about. I have both a dedicated HBC and a pair of top of the range Steiners and I doubt I can do better than 3° either way.

I've knocked up a spreadsheet to work out the bearing angles for a yacht doing 5 knots crossing the path of a ship doing 20 knots as they approach a point of intersection. The bearings (relative to yacht's heading) are shown for a course where the ship passes 400m ahead of the yacht.


Distance Bearing
20 75.29
16 75.12
12 74.85
8 74.29
4 72.65
2 69.44
1 63.43
0.5 53.13
0.25 38.66

(Apologies if your browser doesn't space the table properly)

I would say that most yachtsmen couldn't confidently say there was no risk of collision until the vessels are no more than a mile apart.

 

[Observer]

I'd like to address an issue that is often skimmed over in the discussion of collision courses, i.e. how reliable are your compass bearings? Bear in mind that these situations tend to happen in open sea where a small boat is bouncing about and even the best-damped hand-bearing compass card is wandering about. I have both a dedicated HBC and a pair of top of the range Steiners and I doubt I can do better than 3° either way.

I've knocked up a spreadsheet to work out the bearing angles for a yacht doing 5 knots crossing the path of a ship doing 20 knots as they approach a point of intersection. The bearings (relative to yacht's heading) are shown for a course where the ship passes 400m ahead of the yacht.


Distance Bearing
20 75.29
16 75.12
12 74.85
8 74.29
4 72.65
2 69.44
1 63.43
0.5 53.13
0.25 38.66

(Apologies if your browser doesn't space the table properly)

I would say that most yachtsmen couldn't confidently say there was no risk of collision until the vessels are no more than a mile apart.

Oooh. That's really useful. I was just about to try and work out a similar table myself but didn't think of using a spreadsheet. As you say, the longer range bearing doesn't change by more than could be put down to an "error margin". If you calculated the different bearings on the port and stern of a 200m ship, the differences, at the critical intermediate ranges (4 miles to 1 mile), between two bearings (one on the bow and the next on the stern) would be even smaller, hmm?

 

[benjenbav]

A good deal of this discussion stems from the word "apparent" in Rule 17(a)(ii), which is commonly construed in subjective terms. The correct construction must be an objective one.

This makes it difficult not to think that any case emerging today might be distinguishable from Banshee (which, I think, is actually a Court of Appeal case, and obviously not concerning the current IRPCS) owing to factors such as the different equipment available to the modern mariner - it would not have been possible to track the cpa of a vessel on radar in 1887, for example, not least because radar hadn't been invented. A further distinguishing feature today might well be the consideration of vessels with markedly different handling characteristics, which was not something which needed to be considered in Banshee.

 

[Observer]

A good deal of this discussion stems from the word "apparent" in Rule 17(a)(ii), which is commonly construed in subjective terms. The correct construction must be an objective one.

This makes it difficult not to think that any case emerging today might be distinguishable from Banshee (which, I think, is actually a Court of Appeal case, and obviously not concerning the current IRPCS) owing to factors such as the different equipment available to the modern mariner - it would not have been possible to track the cpa of a vessel on radar in 1887, for example, not least because radar hadn't been invented. A further distinguishing feature today might well be the consideration of vessels with markedly different handling characteristics, which was not something which needed to be considered in Banshee.

I don't agree that "apparent" is capable of objective interpretation ahead of analysis of the facts and circumstances of a specific case. In law, it surely falls to be decided by a court on those established facts, in the same way as (for example) "careless driving" is assessed by the court by reference to the established facts against the standard expected of a "careful and competent driver". It doesn't have an objective meaning outside a courtroom - and even then not until the tribunal of fact has so decided.

 

[bedouin]

A good deal of this discussion stems from the word "apparent" in Rule 17(a)(ii), which is commonly construed in subjective terms. The correct construction must be an objective one.

This makes it difficult not to think that any case emerging today might be distinguishable from Banshee (which, I think, is actually a Court of Appeal case, and obviously not concerning the current IRPCS) owing to factors such as the different equipment available to the modern mariner - it would not have been possible to track the cpa of a vessel on radar in 1887, for example, not least because radar hadn't been invented. A further distinguishing feature today might well be the consideration of vessels with markedly different handling characteristics, which was not something which needed to be considered in Banshee.

Actually I don't think there should be much of an issue with the use of "apparent" in this context. Given that the requirement is for any such manoeuvre to be obvious to the stand on vessel, if it isn't obvious that he has then it must be apparent that he hasn't.

Surely the issue is more about the time at which the manoeuvre should be made - as snowleopard points out it can be hard to know of risk of collision really exists until the vessels are within a mile or two.

 

[Observer]

If that is the case, then why are you so keen to alter course at three miles? Why not let it go for another mile or so, by which time the ship will probably have altered course. If it hasn't, you will have had another mile in which to decide what is really happenning, and you will still have plenty of room left to make what will then be a perfectly legitimate manoeuvre.

Fair question.

First, as I said, the 3 miles range was taken as a hypothetical range at which I may well have concluded my preliminary collision risk assessment. It was not intended to be precise. The actual range could be 4 miles or 2 miles. Indeed, I may not know with any substantial accuracy what the distance is. Why should I need to? It's like the braking/stopping distances in the highway code. They have absolutely no practical relevance or application in everyday driving.

Second, my hypothetical illustration is that it appears that I will pass ahead. But am I sure? Snowleopard's analysis indicates that the actual change in bearing for a CPA of 400m between 4 miles and 2 miles separation is only ~3°. And even if I am sure, does the CPA (which I cannot measure accurately anyway) provide a safety margin that I am willing to accept? I know I said I could manoeuvre out of the way in nearly all cicumstances, but the risk of engine failure or hitting something in the water at the critical moment, even if remote, does exist, so I do not discount it entirely. So my real choice (it seems to me) is to eliminate the possible conflict with certainty (the sooner the better), even if that means [bending the rules a bit] [perhaps "a flexible interpretation" is better], or to wait until the range has reduced to ~1 mile, at which point the avoiding action, if needed, will have to be more substantial.

Third, why is 2 miles the range which I should set as my rule 17(a)(ii) decision point. Why not 2.5 or 1.5? You said (I think) that ship's OOW will usually have commenced avoiding action at ~2 miles, but should I rely on that?

I thought that, too. But whilst we can discuss opinions, there is nothing to be gained by discussing facts: it just becomes boring. And the fundamental fact is the text of Rule 17. We can't change that.

Agreed. But we can debate the interpretation of Colregs. We can debate the scope of meaning of "appreciable" in 7(d)(i) and the intent of "if the circumstances of the case admit" in 17(c). I think you felt it otiose to debate the scope of meaning of "apparent" in 17(a)(ii), but what about "appropriate" in the same rule. We can debate the point at which a CPA crosses the line between "no risk of collision" and "risk of collision"; and whether that distance may or may not vary depending on one's perspective (small vessel or otherwise), appetite for risk or simple subjective judgement. We can also debate whether and how CPA can be reliably measured (by a small vessel or otherwise), and how that influences the interpretation of rule 17 and the previous judgements.

You may be persuaded by my arguments and acknowledge that early avoidance, albeit not in accordance with the narrow interpretation, could, in some cases, actually be 'a good thing', or just an acceptable, practical measure (I'm not holding my breath) . We could debate which of the available alternative avoidance measures is more or less appropriate. I suggested a 10° turn to port, which geometrically would work (comfortably I think) if made at ~3 miles range. However, I can see the argument for a more decisive turn (showing the other bow), hold for a while, then equal and opposite turn back on to original heading. Or something else (I don't like 360° turn for several reasons but it could be discussed). And would that 'appropriate action' be different if the small vessel is a yacht at 5kts rather than a power vessel at substantially greater speed?

Plenty to talk about. I respect your experience and expertise and I am genuinely interested to hear your opinions, but I will keep challenging you to justify them if I see any weaknesses or gaps. That's just the way I am.

 

[benjenbav]

I don't agree that "apparent" is capable of objective interpretation ahead of analysis of the facts and circumstances of a specific case. In law, it surely falls to be decided by a court on those established facts, in the same way as (for example) "careless driving" is assessed by the court by reference to the established facts against the standard expected of a "careful and competent driver". It doesn't have an objective meaning outside a courtroom - and even then not until the tribunal of fact has so decided.

That's really the issue which I was labouring to encapsulate; after the event the court will look at what should have been apparent to me whereas, ahead of the incident I was only able to make a judgment on what was apparent to me.

 

[timbartlett]

Sorry, gentlemen, but I can't cope with all the nested quotes. This post is too long even without them, I have three dogs demanding a walk, and I really do have to do some constructive, money-earning work! So please pick what you can out of this:-

Long ranges
At very long ranges (let's say over 6 miles, partly so that other understand what kind of distance I have in mind, and partly because that's the only figure that is specifically referenced in law), I suggest that both vessels are free to manoeuvre.
At that stage, the small craft probably cannot be certain whether a steady bearing situation exists or does not. But Rule 7di says that we have to deem a risk to exist unless the compass bearing is changing. Fortunately, the MCA's proposed "Long Range Rule" was rejected by IMO, so the precedent is the Banshee case that says you can't collide with a ship that's six miles away. Even without Banshee, if you think you can avoid a collision by allowing your vessel to yaw a few degrees to port, while you are still at 6miles +, who's going to know, and who's going to complain?

Medium ranges
Once the range is <6M, there is no ambiguity. Rule 7di says that we have to assume there's a risk of collision unless we know there isn't. And Rule 17a1 says the stand-on vessel has to stand on if there's a risk of collision.

From the ship's point of view, Rule 8 requires that an alteration of course has to be large enough to be readily apparent to another vessel observing visually or by radar. So if it is not "readily apparent"to the watchkeeper on the stand-on vessel(using an ordinary dictionary interpretation of "apparent")then he isn't obeying the rules.
(It would be up to a court to decide whether 10 degrees was plenty or whether 20 degrees was not enough in any particular situation)

But just because he hasn't apparently altered course when the range is five miles, or four miles, there is no reason to believe that he isn't going to. So Rule 17 a i applies.

By the time the range has closed to three miles, some of us might have just noticed him, some of us might be wondering whether his bearing is changing, and some of us might be wondering why he hasn't altered course yet...but none of us have any reason to believe that he isn't going to. So the obligation imposed by Rule 17 a i still applies.

Short ranges
We are not allowed to alter course until it has become apparent that the stand on vessel is not taking action in accordance with the rules. And we cannot argue that he is not acting in accordance with the rules until the range has closed to such an extent that any normal watchkeeper on a similar ship would have altered course if he was going to. Until that moment, he could be taking bearings, checking with the radar, consulting with the captain, asking the engineroom if it's OK to change engine revs yet, disengaging the autopilot, etc.etc.

The precise moment at which it becomes "too late" depends on the handling charatcteristics of the ship, which we don't know. Normal practice puts it at about two miles in open water. But why argue about precisely where, in this grey area, we cross the dividing line at which 17aii begins to apply?

It's a fairly narrow grey area, and in a small and manoeuvrable craft, there is very little -- if anything -- to be gained by altering course at the earliest possible moment that we are allowed to do so. Why not carry on until there is no doubt? By the time the range has closed to (say) one mile, the watchkeeper on a big, unmanoeuvrable vessel has clearly left it too late, but we still have plenty of time and sea-room available.

My concernsI'm relieved that this discussion has got back to a sensible argument about the issues, rather than personal insults, but I'm afraid I still feel distinctly uneasy about any argument that advocates altering course towards the give-way vessel, at exactly the sort of range at which it is most likely to be altering course itself, and at a stage at which Rule 17 is quite unambiguous.

And whilst it doesn't relate to this particular rule, I can't help thinking of the Wahkuna incident. It's one of very few actual collisions between ships and yachts -- and it would never have happenned if Wahkuna hadn't stopped to give way to an approaching ship.

 

[bedouin]

I am not happy with your view that risk of collision has to be deemed to exist in your "medium range" cases as I think that can lead to very strange consequences. I don't think the courts would interpret the rules as literally as you suggest.

So how do you see this interacting with the "not to impede" regulations?

In particular I don't see how your reading of the rules can be reconciled with Rule 8(f) which clearly suggests that "risk of collision" may develop as the vessels approach - otherwise (iii) does not make any sense at all.

 

[Observer]

I am not happy with your view that risk of collision has to be deemed to exist in your "medium range" cases as I think that can lead to very strange consequences. I don't think the courts would interpret the rules as literally as you suggest.

So how do you see this interacting with the "not to impede" regulations?

In particular I don't see how your reading of the rules can be reconciled with Rule 8(f) which clearly suggests that "risk of collision" may develop as the vessels approach - otherwise (iii) does not make any sense at all.

I may be wrong but I think Tim has indicated that he is unwilling to prolong the discussion, which is a shame because it was interesting. I suppose we can continue to debate without him - BB where are you?

Anyway, I'm rather afraid that the annoying tendency of my vessel "to yaw a few degrees to port" at medium range is unlikely to get fixed very soon. Bu**er. Just hope the purists don't sit on the examination panel for my YM ticket.

 

[timbartlett]

I may be wrong but I think Tim has indicated that he is unwilling to prolong the discussion,

Sorry, Observer, but in this particular instance, you *are* wrong -- and I can say that quite categorically!
For one thing, I'm finding it really interesting, and would be delighted to come back early next week to find it still going.
For another, having let the genie out of the bottle, it's quite beyond my powers to put it back.
And finally ... this thread has generated so much interest that I'm trying to think of some way in which I might persuade one of the magazines to use something like it as a feature.

 

[snowleopard]

Following on from my 'change of bearing' post, this is the strategy I suggest. It doesn't involve ignoring colregs but takes into account the relative speeds of the vessels, plus my ability to stop or turn far quicker than any ship.

1. Stand on until the approaching ship is approx 1 mile away

2. Then start taking bearings

3. If by around 1/2 mile there is still a constant bearing, assume the ship is not going to turn. His ARPA may be telling him he'll miss you but he might also be watching a video or being bloody-minded.

4. Stop and wait until the ship is approx 45° off my bow (still approaching). At this point his superior speed will ensure he passes ahead.

5. Get under way again.

I can stop without altering course on any point of sailing. Others will need to make a turn if sailing with the wind free. When turning, turn enough to show him a different sector of light.

 

[benjenbav]

I'm trying to think of some way in which I might persuade one of the magazines to use something like it as a feature

Tim, I was on the point of having a go at you about this worrying delusion that earning a living is in some way more important than wasting your time on here, but I now see that you've got the issue nicely sorted out.

 

[bedouin]

Following on from my 'change of bearing' post, this is the strategy I suggest. It doesn't involve ignoring colregs but takes into account the relative speeds of the vessels, plus my ability to stop or turn far quicker than any ship.

1. Stand on until the approaching ship is approx 1 mile away

2. Then start taking bearings

3. If by around 1/2 mile there is still a constant bearing, assume the ship is not going to turn. His ARPA may be telling him he'll miss you but he might also be watching a video or being bloody-minded.

4. Stop and wait until the ship is approx 45° off my bow (still approaching). At this point his superior speed will ensure he passes ahead.

5. Get under way again.

I can stop without altering course on any point of sailing. Others will need to make a turn if sailing with the wind free. When turning, turn enough to show him a different sector of light.

The problem with this - and in fact the same is true of almost any action by a stand on sailing vessel, is that if you stop and he takes the action he should do to avoid you (perhaps he has only just realised you are under sail) then you actually make collision more likely (because his action will be to alter course towards you) and, as you have stopped, you are rather limited in your options!

That is particularly the case as it may not be readily apparent to him that you have stopped.

IMHO the only action you should consider taking when he is that close is turning signficantly - either showing him your stern or doing a 180.

In my view if you as stand on vessel decide to take action yourself it must involve a change of course large enough to be immediately apparent to the other vessel, and it must be early enough that should he take action at about the same time there is still time to sort things out before the crunch

 

[Observer]

Sorry, Observer, but in this particular instance, you *are* wrong.

Double bu**er. That hasn't happened before.