Crossing Separation Zones in Small Yacht

[JayBee]

It's not, perhaps, a "definition" in the strict sense of the word, but 8f(i) makes it pretty clear:
- A vessel which, by any of these Rules, is required not to impede the passage or safe
passage of another vessel 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.

In other words, so long as you "allow sufficient sea room for the safe passage of the other vessel" you have fulfilled your obligation not to impede .

It's certainly not an "explicit definition" - more general guidance, in my opinion, and thus open to different interpretations on the bridge and in the cockpit - especially in a busy TSS.

"when required by the circumstances of the case" evidently means different things to different folks posting on this thread.

If there was an explicit definition of "impede" would it not be listed in Rule 3 - Definitions? It isn't.

I don't think I am splitting hairs here.

 

[stephenh]

Good morning ......

OK. Say you are in your small sailing vessel, crossing a separation lane and you have a power driven vessel on a steady bearing on your starboard side. In light of your past experience you hope that she will alter course a few degrees to starboard to avoid a close quarters situation with your yacht. Not withstanding the fact that you may be impeding his ship, the OOW might be happy to do this, but he has another ship overtaking him quite closely on his starboard quarter - for whom he is required by the Rules to maintain his course and speed.

Cockroft + L : Rule 17 - Action by stand-on vessel

"A vessel is only required to maintain her course and speed in a two vessel situation.
In the ... event of one vessel finding herself on a collision course with two other vessels at the same time, being in one case the give-way vessel and in the other case the stand-on vessel, she could not be expected to keep out of the way of one vessel and maintain her course and speed for the other. "

Which brings us to definitions of the word "course" - probably good for another thread ( or two)

 

[JayBee]

Good morning ......



Cockroft + L : Rule 17 - Action by stand-on vessel

"A vessel is only required to maintain her course and speed in a two vessel situation.
In the ... event of one vessel finding herself on a collision course with two other vessels at the same time, being in one case the give-way vessel and in the other case the stand-on vessel, she could not be expected to keep out of the way of one vessel and maintain her course and speed for the other. "

Which brings us to definitions of the word "course" - probably good for another thread ( or two)

Good morning to you..

Can't argue with that. So in the scenario outlined in post 139 (sorry!) the tanker will almost certainly keep her course and speed for the overtaking vessel and the yacht then has to decide whether to continue into an impeding situation, or do something about it. (It is possible that the yacht can't even see the vessel overtaking the tanker, or know the distance between the two ships.)

 

[stephenh]

Good morning to you..

Can't argue with that. So in the scenario outlined in post 139 (sorry!) the tanker will almost certainly keep her course and speed for the overtaking vessel and the yacht then has to decide whether to continue into an impeding situation, or do something about it. (It is possible that the yacht can't even see the vessel overtaking the tanker, or know the distance between the two ships.)

I’ve been there and done that ..... Just off the end of a TSS

I was sailing and stood on to a tanker coming up from starb’d. However, she stood on (disobeying18 iv but obeying 17a i, as it turned out) . I was expecting the usual give way but no…so 17 b kicks in and I headed for her stern.
As she cleared me there appeared behind her, and heading straight for me , the mother of all tankers which I could not have seen except with Radar.

17 b again (for me), crash tacked and sailed away.

A few humourous comments ensued on the VHF with everybody thanking everybody else.
Should I have headed for the first stern earlier ?
No I don’t think so with the scant information that I had. Different if there had been Radar of course.

 

[BrianH]

Should I have headed for the first stern earlier ?
No I don’t think so with the scant information that I had. Different if there had been Radar of course.

Or much better still, an AIS receiver display. Much cheaper, much less power requirement.

 

[timbartlett]

...
- A vessel which, by any of these Rules, is required not to impede the passage or safe
passage of another vessel 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.

In other words, so long as you "allow sufficient sea room for the safe passage of the other vessel" you have fulfilled your obligation not to impede .

...If there was an explicit definition of "impede" would it not be listed in Rule 3 - Definitions? It isn't.

I don't think I am splitting hairs here.

There are lots of words and expressions used in the colregs that are not defined in Rule 3 -- the terms "give way" and "stand on" are good examples!

Where words are not explicitly defined , I would assume that the idea is that we should interpret them with their ordinary, everyday english meanings, rather than scratching around for alternatives that will completely invert the meaning of the rules.

Rule 8 says that the "shall not impede" vessel (the "SNIV" is required to allow sufficient sea room for the passage of the vessel not to be impeded (the "VNTBI"). If it intended that the SNIV should give way to the VNTBI, why does the rule not simply say so?
And if the intention was that the SNIV should navigate so as to allow the VNTBI to maintain its course and speed, why is that not included in Rule 3? If your argument is to hold water, it certainly should be, because it is a meaning of "impede" that goes far beyond "allowing sea room".

 

[JayBee]

stephenh

Yes. Good argument for AIS and Radar if sailing frequently in heavy traffic.

Recently I was the meat in the sandwich between the Eugen Maersk, one of the six largest container ships in the world and another ship off Finisterre. (Not in the TSS).

I called both of them and got very friendly and polite responses. It was easy to sort out and both ships gave me a wide berth, although I would have agreed to keep clear of them, if asked to do so.

 

[JayBee]

timbartlett

There are lots of words and expressions used in the colregs that are not defined in Rule 3 -- the terms "give way" and "stand on" are good examples!

"give way" and "stand on" are part of the ordinary language of seamen.

"impede" is a concept with (obviously, from this thread) a variety of possible interpretations.

 

[JayBee]

timbartlett

Rule 8 says that the "shall not impede" vessel (the "SNIV" is required to allow sufficient sea room for the passage of the vessel not to be impeded (the "VNTBI"). If it intended that the SNIV should give way to the VNTBI, why does the rule not simply say so?
And if the intention was that the SNIV should navigate so as to allow the VNTBI to maintain its course and speed, why is that not included in Rule 3? If your argument is to hold water, it certainly should be, because it is a meaning of "impede" that goes far beyond "allowing sea room".

The getout clause in the IRPCS, for the apportionment of blame and the livelihood of lawyers is this (Rule 8 (f) (i):

A vessel which, by any of these Rules, is required not to impede the passage or safe passage of another vessel 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.

 

[timbartlett]

"E=Marsupial;3359240]you still bang on about AIS, yet in two incidents, the Liquid Metal thing that according to AIS sailed over the Dungeness power station, and proceeded easterly down the A27 or was it the A25? and the Costa cruise ship that according to AIS missed the rocks by 155 mtrs; clearly AIS is not up to the job.

think eyeballs and radar you wont go far wrong.

AIS is still a ("dangerous") work in progress?[/QUOTE]
AIS is a communication system reporting position data is derived from the on-board GPS receiver. If the GPS receiver is providing duff information, that is the GPS's fault , not AIS. GPS is not perfect, but it is generally pretty good.

A lot of the misleading information that is put oout about AIS comes from people whose experience of the system other than what they see on websites purporting to show "live" ship movements -- but which update far more slowly than onboard systems and usually (always?) include a deliberate delay.


"

 

[timbartlett]

"give way" and "stand on" are part of the ordinary language of seamen.

"impede" is a concept with (obviously, from this thread) a variety of possible interpretations.

I agree that "give way" and "stand on" are part of the ordinary language of seamen, but it seems that they are also open to a variety of possible interpretations amongst forumites.

"Stand on" in particular, seems to be widely interpreted as meaning "alter course to port whenever you see a vessel that is bigger than you".

 

[GrahamM376]

I agree that "give way" and "stand on" are part of the ordinary language of seamen, but it seems that they are also open to a variety of possible interpretations amongst forumites.

"Stand on" in particular, seems to be widely interpreted as meaning "alter course to port whenever you see a vessel that is bigger than you".

Can't help but wonder how many forumites have actually crossed a busy shipping lane or TSS.

Big ships don't just appear out of nowhere and when closing them from a distance, you have the same choice as when approaching a fairway buoy - do I pass to port or starboard of it? In the case of a large vessel I just adjust my course to pass his stern rather than the bow which may well cause him to alter course. Is this so difficult to understand or do?

I don't have much time for the attitude shown by some yachtsmen that "I'm under sail and WILL NOT alter course for anyone"!!!

Radar is a good help but sometimes, with a big return, the screen can be blacked out in a complete circle and another vessel (as already mentioned in a previous post) can be hiding behind the nearest.

 

[Simondjuk]

It is difficult to understand, yes. For the OOW of the ship, that is. How does he know what your intentions are?

The very point of the IRPCS is that they allow every vessel to know what to expect of every other, without recourse to direct communication and with the minimum of confusion or ambiguity. The moment you deviate from the regulations, you remove all those facilities.

 

[GrahamM376]

It is difficult to understand, yes. For the OOW of the ship, that is. How does he know what your intentions are?

The very point of the IRPCS is that they allow every vessel to know what to expect of every other, without recourse to direct communication and with the minimum of confusion or ambiguity. The moment you deviate from the regulations, you remove all those facilities.

He can see you coming in from some distance, by eye and radar and see that your course will take you across his stern.

Quoting IRPCS in many instances is a red herring. I will have had the EBL on any conflicting traffic from most likely 8 miles. If my track is at right angles to the ships course and I'm 3-4 miles away from the point at which we will meet, it's going to be 20-30 minutes or so before we do so. To set my course at that distance to pass his stern is not a deviation from IRPCS and he's highly unlikely to have instituted a course change by then. If however he has done (which I've never seen at that distance) I would then stand on.

 

[JayBee]

I agree that "give way" and "stand on" are part of the ordinary language of seamen, but it seems that they are also open to a variety of possible interpretations amongst forumites.

"Stand on" in particular, seems to be widely interpreted as meaning "alter course to port whenever you see a vessel that is bigger than you".

 

[Ex-SolentBoy]

I have a sneaking suspicion that many of these crossing situation problems are in fact caused by too much changing of course and over thinking the problem.

For the average small sailboat, say travelling a 5 knots at right angles to a large tanker or whatever, the actual period of danger is only the few seconds that it takes to travel the distance of the beam of the ship, plus a safety margin, for the short period of time that the ship is passing you.

I am sure someone better at maths than me could calculate this.

In practice to me, that means I do not alter course or slow down ever until I am quite close. 9 times out of ten the ship passes way before I get there. The other time a quick tweak of the helm, or closing of the throttle means I pass behind.

I have AIS and radar both capable of CPA, but I tend to just let the situation develop and make a single action at the right time if need be.

So far, no commercial ship has misunderstood this and turned towards me.

 

[timbartlett]

...in two out of two times AIS has had a high media profile and has been found wanting its because someone has not read the chart properly or has misinterpreted it? I dont understand your point, we are looking at published tracks, historical data, or should we change that data so it accords with the facts in which case the system collecting is still wrong - for what ever reason.

I have experience of Decca, Loran, GPS, AIS and paper charts and in my experience (until I looked for the concordia was all live on board) they all have a problems.

In particular the AIS track published on various web sites of the Concordia roughly accords with the accuracy of charts/systems generally I have experienced in the med. ie only just good enough, a 155mtr error re GPS, chart and chart plotter and actual position is commonplace. and no its not a chart datum setup issue, its the charts, they are not correct, correct the error in one location another error will appear in somewhere else, you cant rely on them to within a few 100 mtrs or so. its not the solent.

So in para 1 of your post you blame AIS, but in para 3 you blame the charts.
I say again: AIS reports GPS data. If the charts on which the data is overlaid are wrong, that is not a problem with AIS

anyway crossing the TSS unless its foggy is no big deal if you keep to the rules and keep a lookout. I am with Graham376 on this.

Again you contradict yourself: do you agree with Graham 376? Or do you keep to the rules?

 

[sailorman]

I agree that "give way" and "stand on" are part of the ordinary language of seamen, but it seems that they are also open to a variety of possible interpretations amongst forumites.

"Stand on" in particular, seems to be widely interpreted as meaning "alter course to port whenever you see a vessel that is bigger than you".

 

[davidej]

Can someone explain what is a 'traffic lane' for the purposes of the colregs. Obviously it includes but is not restricted to a TSS.

If I am not in a TSS, how do I know I am crossing a lane and have an obligation 'not to impede'?

 

[Skysail]

My interpretation is that a TSS has two lanes - in the Channel there is west going lane and an east going lane. I am happy to be corrected!