Colregs Puzzle

[Dockhead]

Originally Posted by rebel heart

Well, that thread has a few modifiers:

- "right of way" indicates that the person really isn't hip to colregs, but that's beside the point
- the 45' sailboat (under power, so it's a power vessel) "sped up" to overtake the smaller sailing vessel, immediately placing it in the lowest order of priority.
- the 45' power vessel would have needed to sound signals or use the vhf to arrange passage and should only have done so after the sailing vessel confirmed the arrangement.

So that's an overtaking situation. Also, a 45 sailing vessel, at least around here, is hardly going to be "confined to a channel" that a 20' sailboat is able to tack around in with reckless abandon. The channel is dredged to 7' but on the sides it's 4'?

I agree completely (other than the last two sentences -- second-guessing the assumed facts, which would make it a different question). But the thread had evolved quite a ways from the OP's particular case, and the question is now different -- Rule 9 versus Rule 18. What do you think?

[markpierce]

The problem with sailboats (particularly under 40-feet in length), from a motorboat point of view, is that they are frequently altering course, wiggling as it is, particularly windward, that it is sometimes difficult to determine, without major course revision, which course is safe to avoid the errant vessel.. Why do some sailboaters continue to luff and then come to a broad reach to only luff again?

Stand-on vessels are supposed to maintain course, right?

[Dockhead]

Originally Posted by markpierce

The problem with sailboats, from a motorboat point of view, is that they are frequently altering course, wiggling as it is, particularly windward, that it is sometimes difficult to determine which course is safe.

Yes, very much so. Not only wiggling around when hard on the wind (an inevitable result of following the wind), but yawing around and doing the other stuff we do when sailing. And on top of that, unexpected sudden maneuvers because of the inexperience of the skipper.

And so all theoretical approaches to crossing situations with sailboats run into certain limitations of practical application (which is not, however, to say that this lets you off the hook for thoroughly understanding the theory). The captain of a large commercial vessel told me that in crossing situations with sailboats, he often intentionally waits until he is 2 or 3 miles off before altering course to avoid a sailboat -- so that there is already no unexpected maneuver the sailboat can make which would put him back in the danger zone.

But this is in the wrong thread -- go here: http://www.cruisersforum.com/forums/...-89285-22.html

[Wotname]

Originally Posted by Dockhead

This is the revival of an old theme, but still interesting and basically unanswered. Anyone have an informed opinion?


.............

All of this seems fairly clear to me from the plain meaning of the Colregs (to the extent they can be said to have plain meaning at all). But some of participants in our forum violently disagree. There exists a view, strongly held, that the sailing vessel in the hypothetical encounter can somehow be the stand-on vessel pursuant to its privilege under Rule 18 even though it may be burdened at the very same time by an obligation to not impede under Rule 9. In support of this position, comments by Cockcroft and Lameijer, in A Guide to the Collision Avoidance Rules, are offered, which imply that contrary to my view, the sailing vessel in our situation which is burdened by a Rule 9 obligation to not impede will nevertheless become the stand-on vessel under Rule 18 once the encounter develops into a risk of collision, which thus burdens the motor vessel even as the motor vessel continues to be privileged by Rule 9. This, to my mind, absurdity – how can the sailing vessel simultaneously stand-on and yet avoid impeding the motor vessel? -- is explained away by Cockcroft and Lameijer by the fact that a stand-on vessel is permitted to take action itself by Rule 17(a)(ii). To my mind this patently weak argument is entirely contradicted by the phrase in Rule 18 which says “except when Rules 9, 10, and 13 otherwise imply”, which establishes priority of Rule 9 over Rule 18, but obviously not everyone accepts this, including some of our most esteemed forum participants, and some authorities at the exalted level of Cockcroft and Lameijer.

I can't help you with an informed opinion but of course I do have an opinion which I will share anyway

Seems straightforward to if we use the usual meaning of the words in rule 9. Rule 9 becomes the only rule in force, rule 18 simply does not apply.
I would think that "risk of collision" would qualify as "impeding" the MV so rule 9 remains in force. Rule 17(a)(ii) can be applied in parallel to rule 9 but never overrides it. The SV has many opinions available to it under rule 17(a)(ii) but must chose one that doesn't contravene rule 9.

The matter can only truly resolved by precedent law, if it exists or otherwise determined by a new case. Then the outcome will go to the party with the most expensive counsel and thus perhaps to whoever engages Cockcroft and Lameijer as expert witness

[Dockhead]

Originally Posted by jackdale

The oterms "burdened" and "privileged" are no longer used in IRPCS.


Is the MV showing a cylinder? If not is it not CBD.

Rule 9(b) rules



See also

Rule9.html

The Nav Rules Handbook supports my position. It says, in the quoted link:

"If your vessel is directed not to impede another, try to avoid causing the other vessel to change its course or speed. If you blunder into a risk-of-collision situation, the general Steering and Sailing Rules will not apply to you--you will continue to be obliged to stay out of the way."

So at least according to this source, Rule 9 trumps Rule 18, and not the other way around.

However, there is this bit:

(iii) A vessel the passage of which is not to be impeded remains fully obligated to comply with the Rules of this part when the two vessels are approaching one another so as to involve risk of collision.

Rule 8(f)(i)(iii).

Seems to be a big, fat contradiction. Truly a puzzle!

[Lodesman]

The 'not impede' requirement is very different from the 'stay out of the way' or the 'stand-on/give way' requirements. Too many here assume that it is the same. Dockhead alludes to the "authority" assessment, but doesn't provide it. In a nutshell, 'not impede' means leaving sufficient searoom, ie. not forcing the vessel out of the traffic lane, into shoal water or against any other navigational hazard. The example I used before:

A sailboat, moving slowly due to wind and current is 500 yards inside the outer limit of a 2-mile wide traffic lane. The lane is deep and free of navigational hazards across its breadth. A containership comes out of the haze 3 miles away going 18 knots, 400 yards inside the outer limit. The sailboat can not be considered to be impeding, because there is more than a mile and a half of safe water between the sailboat and the inner limit of the lane, in which the containership can safely pass, avoiding the sailboat by several hundred yards and remaining well within the traffic lane. The containership must keep clear of the sailboat. The sailboat should stand-on.

If the lane is only 1000 yards wide, and the sailboat is right in the centre of it, when the containership comes out of the haze (as above), then it is incumbent on the sailboat to do what it can to increase the amount of sea-room. Regardless, the containership is required to take action to avoid the sailboat. The containership might(should) slow down and steer to one side or the other of the sailboat. Throughout this, the sailboat is still required to do what it can to give the big ship more room to pass.

I was hoping that Dockhead got a response from some respected authority, rather than polling the peanut gallery again.

[jackdale]

Originally Posted by Dockhead

However, there is this bit:

(iii) A vessel the passage of which is not to be impeded remains fully obligated to comply with the Rules of this part when the two vessels are approaching one another so as to involve risk of collision.

Rule 8(f)(i)(iii).

Seems to be a big, fat contradiction. Truly a puzzle!

Not really The rules have to be considered in total.

Rule 2 - Responsibility

(a) Nothing in these Rules shall exonerate any vessel, or the owner, master, or crew thereof, from the consequences of any neglect to comply with these Rules or of the neglect of any precaution which may be required by the ordinary practice of seamen, or by the special circumstances of the case.

(b) In construing and complying with these Rules due regard shall be had to all dangers of navigation and collision and to any special circumstances, including the limitations of the vessels involved, which may make a departure from these Rules necessary to avoid immediate danger.

Avoid collisions.

That is why is most cases of which I am aware, collisions result in shared responsibility / fault.

[jackdale]

It is important to remember that stand-on and give-way are not the only terms used in describing collision avoidance in the US Rules. (easier to search)

Stand-on is used twice (both times in headings)

Give way is used 4 times (twice in headings)

Keep out of the way is 16 times .

Impede is used 8 times.

[Wotname]

Originally Posted by Lodesman

The 'not impede' requirement is very different from the 'stay out of the way' or the 'stand-on/give way' requirements. Too many here assume that it is the same. Dockhead alludes to the "authority" assessment, but doesn't provide it. In a nutshell, 'not impede' means leaving sufficient searoom, ie. not forcing the vessel out of the traffic lane, into shoal water or against any other navigational hazard....

Given that "not impede" has a different meaning to "stand on / give way" etc (otherwise the phrase would not have been used ) but do any of the CR gurus know if the term is defined within the CRs. I have not seen it so defined within the CRs but that is not surprising given my sketchy knowledge of fine detail of the CRs.

If it is not defined in the CRs, then does it have a special legal meaning or are we just left with the dictionary meaning?

[Dockhead]

Originally Posted by Lodesman

The 'not impede' requirement is very different from the 'stay out of the way' or the 'stand-on/give way' requirements. Too many here assume that it is the same. Dockhead alludes to the "authority" assessment, but doesn't provide it. In a nutshell, 'not impede' means leaving sufficient searoom, ie. not forcing the vessel out of the traffic lane, into shoal water or against any other navigational hazard. The example I used before:

I was hoping that Dockhead got a response from some respected authority, rather than polling the peanut gallery again.

I will get in touch with Cockburn again and try again to get some response out of the RYA. I think I can formulate the question well enough now not to be ashamed.

Here is some further insight in the matter of how 'not impeding' interacts with the 'stand-on/give way' rules:

"The IMO Subcommittee on Safety of Navigation for a time had issued guidance on the meaning of the term 'shall not impede.' That guidance said that the 'shall not impede' command meant to maneuver, when practicable, so far out of the way of the other vessel that risk of collision never develops, with the proviso that if risk of collision by some chance does develop, the more general Steering and Sailing Rules would take over (that is, the 'shall not impede' rules would no longer be in effect).


"The IMO subsequently decided that the guidance, if given at all, should be part of the Rules. During the course of the debate on the actual language, the delegates decided that the vessel that had been originally directed to not impede the other should retain that burden even after risk of collision arose. That does not mean, however, that the (usually larger) vessel that was not to be impeded continues to have the right of way. The new Rule provides that if the not-to-be-impeded vessel would be the give-way vessel under the general rules, it has the duty to stay out of the way of the impeding vessel after risk of collision arises. Under the new Rule, which changed the earlier official guidance in this respect, the impeding vessel also continues to have a duty to stay out of the way after risk of collision arises, and does not gain the stand-on status that the general rules might have given it. Both vessels would be obligated to stay out of the way.


"If on the other hand, the not-to-be-impeded vessel would be the stand-on vessel under the general Steering and Sailing Rules, it would not lose that status. In that case, the impeding vessel would have a double duty to stay out of the way.


The 'shall not impede' language in these cases creates an exception to the general rules, making them more practical. Vessels directed 'not to impede' other vessels should take early action to keep clear by wide margins. The other vessel shouldn't become concerned enough to alter its course or speed, or otherwise feel obligated to act differently from the way it would if the would-be impeding vessel weren't there."


Rule8.html


So -- if this report is right -- then Lodesman was right at the time, probably, he learned the opinion he was arguing so vociferously a couple of years ago on the old thread.



But now the rules (as officially interpreted) have changed -- the sailboat in our hypothetical case is definitely not the stand-on vessel. Lodesman is therefore not right today, if this article is right.


To the extent I said that the vessel navigating in the narrow channel was the stand-on vessel, then I was wrong. To the extent I said that the sailboat was not the stand-on vessel, I was right.


Let's see what Cockburn says, and I'll try again to get a response out of the RYA.


Before the "just get out of the way" brigade gets all stirred up again, a vessel navigating in a narrow channel which cannot safely navigate outside it can make at least one meaningful anti-collision maneuver -- it can change speed. So if both vessels are obligated to maneuver as the Nav Rules Handbook claims, this is not a trivial difference compared to what I originally thought -- that the sailboat is a give-way vessel. I was wrong about that (again, if Nav Rules Handbook is right), and my hat is off to Lodestar who clearly understood the issue better than I did when we started arguing about it. Even if he is wrong today . I've sure learned a lot from this.

The fact that even those who wrote the rules were puzzled by this question is also a certain consolation

[donradcliffe]

In a practical sense, 'shall not impede' means you should never require the ship to give the 5 blasts.

[Dockhead]

More information on the question:

"There is a definition of 'impede' (of sorts) ... but it's in Rule 8, not in the definitions!

"It says 'A vessel which, by any of these rules, is required not to impede the safe passage of another shall, when required by the circumstances of the case, take early action to allow sufficient sea-room for the safe passage of the other vessel'

"That, according to my reading, means that so long as the smaller vessel leaves enough room for the larger one to be able to manoeuvre according to the colregs without putting itself in danger, then it has fulfilled its obligation.

"But when I was writing my colregs book, I wrote to the MCA asking for clarification on this aspect of rule 10 and what I got back was a verbatim quote from Cockroft and Lameijer! So I decided to play it safe and recommend that 'you should take avoiding action sufficiently early that the question of whether there is a risk of collision or which is the give-way vessel simply does not arise.' This is very much in line with a guidance note that was issued by the IMO in the early 80s, and I suspect it is probably the basis of the MCA and Cockroft and Lameijer interpretations as well.

"But the fundamental point of Dag's article is true: Rule 10 is a mess. It may have 'done its job' in reducing collisions, but its requirements for vessels under 20m are almost unintelligible and its requirements for those only just over 20m are potentially dangerous. "

From: Colregs and TSS - Page 3 - Yachting and Boating World Forums

I think this conversation predates the last IMO note so is probably obsolete, but the conversation well illustrates the problem!

[Wotname]

Originally Posted by Dockhead

More information on the question:

"There is a definition of 'impede' (of sorts) ... but it's in Rule 8, not in the definitions!

"It says 'A vessel which, by any of these rules, is required not to impede the safe passage of another shall, when required by the circumstances of the case, take early action to allow sufficient sea-room for the safe passage of the other vessel'

"That, according to my reading, means that so long as the smaller vessel leaves enough room for the larger one to be able to manoeuvre according to the colregs without putting itself in danger, then it has fulfilled its obligation.

"But when I was writing my colregs book, I wrote to the MCA asking for clarification on this aspect of rule 10 and what I got back was a verbatim quote from Cockroft and Lameijer! So I decided to play it safe and recommend that 'you should take avoiding action sufficiently early that the question of whether there is a risk of collision or which is the give-way vessel simply does not arise.' This is very much in line with a guidance note that was issued by the IMO in the early 80s, and I suspect it is probably the basis of the MCA and Cockroft and Lameijer interpretations as well.

"But the fundamental point of Dag's article is true: Rule 10 is a mess. It may have 'done its job' in reducing collisions, but its requirements for vessels under 20m are almost unintelligible and its requirements for those only just over 20m are potentially dangerous. "

From: Colregs and TSS - Page 3 - Yachting and Boating World Forums

I think this conversation predates the last IMO note so is probably obsolete, but the conversation well illustrates the problem!

Can I infer from this that the implied meaning is "stay well away from the narrow channel"

[Ex-Calif]

Why was the term "Shall not impede" used? We already have good terms like keep clear and give way.

We are assuming a crossing situation. Here in our channel the ships are all restricted. They also have to go 5 knots in order to steer, they also have to add 2+ knots when down current. So they go 7-8 knots. Some of them speed and we have tracked them on AIS at 10 knots SOG.

To me the "impede" word conotates, "slow down" i.e. you can't toodle along in the channel at 3 knots in a drift and "slow down" the ships that are restricted and following you.

i.e. - get out of the channel...

This is an interesting interpretation because it implies not just giving way but "requires" a positive action to get out of the way - and clear the channel for example.

The crossing rules are clear. He is stand on and sailboat is give way regardless of port starboard.

[nigel1]

Originally Posted by Dockhead

Before the "just get out of the way" brigade gets all stirred up again, a vessel navigating in a narrow channel which cannot safely navigate outside it can make at least one meaningful anti-collision maneuver -- it can change speed. So if both vessels are obligated to maneuver as the Nav Rules Handbook claims, this is not a trivial difference compared to what I originally thought -- that the sailboat is a give-way vessel. I was wrong about that (again, if Nav Rules Handbook is right), and my hat is off to Lodestar who clearly understood the issue better than I did when we started arguing about it. Even if he is wrong today . I've sure learned a lot from this.

The fact that even those who wrote the rules were puzzled by this question is also a certain consolation

Slowing down the bigger vessel in a channel to avoid collision happens quite often, well, to me it does.
A prudent mariner will have engine/s ready for immediate manoeuvring (note, large vessels need to bring engine speed down slowly to what is referred to as harbour speed, sudden speed reduction from full sea speed can damage the engine)
Also note Rule 6 Safe Speed, and again Rule 8(e) If necessary to avoid collision or allow more time to asses the situation, a vessel may slacken her speed or take all way off by stopping or reversing her means of propulsion.

In navigating larger vessels in narrow channels, risk of collision takes place at much lesser distance than in open waters. If the SV has not avoided to impede the passage of the larger vessel, the larger vessel has to take action, and in most cases, this will mean reducing speed. A course alteration to starboard may well be out of the question, as in theory, the larger vessel should already be as near as practical on the starboard side, and will not have the water depth that way. An alteration to port is also to be avoided, as the SV may well make the last minute turn to starboard.
On many occasions in narrow channels I have been forced to get the speed off quickly and allow an offending vessel to pass ahead. There is also very little time to get on the VHF, i) You are now distracted and doing something other than avoiding collision where seconds count, ii) In narrow channels, especially busy commercial rivers, VHF traffic can be heavy.
In well run commercial channels, and the Nieuwe Waterweg canal is a good example, they have very good VTS, and VTS will try and warn away smaller craft. If they dont succeed, you know well enough that you'll have to take action.