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Old 20-09-2013, 09:20   #181
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Re: What can happen when you cut off a ferry

Those are some busy channels! We have been through there numerous times and even with two people watching out it feels like you are still missing boats. Bummer situation.
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Old 20-09-2013, 09:27   #182
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Re: What can happen when you cut off a ferry

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Originally Posted by boatman61 View Post
....??

You sly dog -- you certainly know how to keep a watch!
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Old 20-09-2013, 09:30   #183
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Re: What can happen when you cut off a ferry

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Those are some busy channels! We have been through there numerous times and even with two people watching out it feels like you are still missing boats. Bummer situation.

It sounds like a miserable place to sail. Will it take you to less congested waters?
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Old 20-09-2013, 09:39   #184
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Re: What can happen when you cut off a ferry

[QUOTE=Dockhead;1344554]
First of all, if you invent and then follow a simple rule of "just get out of the way", you will often be in violation of the rules, and you will often create dangerous situations. The rules do not boil down to anything like this and you cannot substitute this nonsense for knowing them.

Second, "just get out of the way" will not save you in very many situations as a simple result of the geometry of a crossing with a larger, faster vessel. An overtaking case like the OP's case is an excellent example. If you are being overtaken by a large, fast commercial vessel, you MUST hold your course and speed as required by the rules so that you don't mess up the commercial vessel's calculation of the crossing. In such a case, it is just about impossible for the overtaken small sailboat to do anything, because by the time you recognize that the overtaking vessel is not avoiding you, you already cannot, in most cases, get clear. So overtaking of a small, slow vessel by a large, fast one is a rare case where the responsibility is almost 100% on the overtaking vessel, simply because the overtaken vessel has almost no means to do anything.

Why is that? At 5 knots, say, you move 0.83 cables per minute or about 2.6 meters per second. If you have a maximum rate of turn of 12 degrees per second, then you can turn 90 degrees to your former course in 7.5 seconds. So to get clear of a vessel bearing directly down on your stern, and which has a beam of 25 meters -- if being "clear" means say 50 meters from the ship's side (less than that and you'll be sucked into the bow wave, and even that is not really a safe distance) -- then you need about 35 seconds.

That vessel bearing down on you at 20 knots is moving at more than 10 meters per second. So in the 35 seconds it takes you to get sort of clear, that vessel will have moved more than 350 meters which is almost two cables (!). So if you are going to "just get out of the way", you will need to have precise data about his course, and you will need to have determined which way to "dodge", and you will have needed to have calculated all that no later than by the time he is at least 2 cables off. And you also need to be absolutely certain that he is holding his course. And if you screw up the calculation, if you have even slightly erroneous data, or if you are wrong about whether or not he is holding his course, then you have a 50/50 chance of dodging not to safety, but right under his bows.

THAT is why you are required to hold your course and speed while being overtaken until you are "in extremis". Since when you are in extremis is already too late to do anything, in most cases, in this kind of overtaking situation, for the geometrical reasons explained above, there is rarely anything for a slow, small vessel in an overtaking situation to do but hold course and speed so you don't screw up the maneuver of the overtaking vessel.

I say again -- the rules require you to hold course and speed when being overtaken until you are sure that the other vessel is not maneuvering. The rules do not permit you to dodge around willy-nilly according to your own invented rules. And in fact, dodging around willy-nilly, "just keeping out of the way", is reckless bad seamanship, the kind of behavior commercial mariners hate us for.The only time we are permitted to "just keep out of the way" is prior to a risk of collision arising -- meaning, staying out of a channel, for example, in the first place, in a harbor situation, something we all do when we can. In open water, that moment will usually have come and gone before you ever know the commercial vessel is there, unless you have AIS and are keeping a sharp watch on it.

So ALL OF THAT is why saying "just get out of the way" is dangerous bad advice, wrong advice, which could kill someone. Which is why I cannot be silent while this pernicious foolishness is touted in these pages.[End quote]

*

Dockhead, you routinely sail in a region where knowing the Colregs can save your bacon. I think the excerpts above from your post are extremely important for people to understand, especially before they leave for high shipping density areas.

It may be that until one has experienced the high speed ferry dangers, the "just get out of the way" advocates have difficulty visualizing that the Colregs can save their lives only if they stand on. Few people use the terms, except the professionals and those others who have educated themselves.
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Old 20-09-2013, 09:56   #185
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Re: What can happen when you cut off a ferry

[QUOTE=Ann T. Cate;1344695]
Quote:
Originally Posted by Dockhead View Post
First of all, if you invent and then follow a simple rule of "just get out of the way", you will often be in violation of the rules, and you will often create dangerous situations. The rules do not boil down to anything like this and you cannot substitute this nonsense for knowing them.

Second, "just get out of the way" will not save you in very many situations as a simple result of the geometry of a crossing with a larger, faster vessel. An overtaking case like the OP's case is an excellent example. If you are being overtaken by a large, fast commercial vessel, you MUST hold your course and speed as required by the rules so that you don't mess up the commercial vessel's calculation of the crossing. In such a case, it is just about impossible for the overtaken small sailboat to do anything, because by the time you recognize that the overtaking vessel is not avoiding you, you already cannot, in most cases, get clear. So overtaking of a small, slow vessel by a large, fast one is a rare case where the responsibility is almost 100% on the overtaking vessel, simply because the overtaken vessel has almost no means to do anything.

Why is that? At 5 knots, say, you move 0.83 cables per minute or about 2.6 meters per second. If you have a maximum rate of turn of 12 degrees per second, then you can turn 90 degrees to your former course in 7.5 seconds. So to get clear of a vessel bearing directly down on your stern, and which has a beam of 25 meters -- if being "clear" means say 50 meters from the ship's side (less than that and you'll be sucked into the bow wave, and even that is not really a safe distance) -- then you need about 35 seconds.

That vessel bearing down on you at 20 knots is moving at more than 10 meters per second. So in the 35 seconds it takes you to get sort of clear, that vessel will have moved more than 350 meters which is almost two cables (!). So if you are going to "just get out of the way", you will need to have precise data about his course, and you will need to have determined which way to "dodge", and you will have needed to have calculated all that no later than by the time he is at least 2 cables off. And you also need to be absolutely certain that he is holding his course. And if you screw up the calculation, if you have even slightly erroneous data, or if you are wrong about whether or not he is holding his course, then you have a 50/50 chance of dodging not to safety, but right under his bows.

THAT is why you are required to hold your course and speed while being overtaken until you are "in extremis". Since when you are in extremis is already too late to do anything, in most cases, in this kind of overtaking situation, for the geometrical reasons explained above, there is rarely anything for a slow, small vessel in an overtaking situation to do but hold course and speed so you don't screw up the maneuver of the overtaking vessel.

I say again -- the rules require you to hold course and speed when being overtaken until you are sure that the other vessel is not maneuvering. The rules do not permit you to dodge around willy-nilly according to your own invented rules. And in fact, dodging around willy-nilly, "just keeping out of the way", is reckless bad seamanship, the kind of behavior commercial mariners hate us for.The only time we are permitted to "just keep out of the way" is prior to a risk of collision arising -- meaning, staying out of a channel, for example, in the first place, in a harbor situation, something we all do when we can. In open water, that moment will usually have come and gone before you ever know the commercial vessel is there, unless you have AIS and are keeping a sharp watch on it.

So ALL OF THAT is why saying "just get out of the way" is dangerous bad advice, wrong advice, which could kill someone. Which is why I cannot be silent while this pernicious foolishness is touted in these pages.[End quote]

*

Dockhead, you routinely sail in a region where knowing the Colregs can save your bacon. I think the excerpts above from your post are extremely important for people to understand, especially before they leave for high shipping density areas.

It may be that until one has experienced the high speed ferry dangers, the "just get out of the way" advocates have difficulty visualizing that the Colregs can save their lives only if they stand on. Few people use the terms, except the professionals and those others who have educated themselves.

Actually I've been on those ferries, and I do realize how fast they go. I wouldn't be anywhere near them. You only have to determine who is "stand on" if there is real risk of collision. What Dockhead has been ignoring the whole way is that the first and best strategy is to not be in that situation.

We know the sailor was not paying attention. If I did think we were on a possible collision course, I would be on the radio to that ferry. I wouldn't have my head buried in electronics in such a congested zone.

My strategy would be to avoid that risk of collision. That requires that one keep a watch in 360. This is also a situation where i think a well-used chart plotter has an advantage, as it will give you a quick glimpse of where you are, and having thoroughly studied the paper chart you would have no trouble fitting that screen into the bigger picture.

This whole thing is amazing because the sailor claims 50 years familiarity with the waters there. I think it's easy to tune out risks when you take them all the time. One of the most dangerous things you can do your boat is step on or off, but how many of us actually think about that as we're doing it?
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Old 20-09-2013, 10:42   #186
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Re: What can happen when you cut off a ferry

[QUOTE=Ann T. Cate;1344695]
Quote:
Originally Posted by Dockhead View Post

Dockhead, you routinely sail in a region where knowing the Colregs can save your bacon. I think the excerpts above from your post are extremely important for people to understand, especially before they leave for high shipping density areas.
I sail in the world's busiest shipping lane, so over here, of course, it is a matter of life and death to get it right. Crossing the Channel in a sailboat has been compared to being a squirrel trying to run across a busy motorway -- a very apt description, as you may have crossing situations with 10 or even more high speed ships on any given crossing. "Just get out of the way" could only be implemented by never leaving port, and just dodging willy-nilly would get you under the bows of a different ship, if it didn't put you under the bows of the ship you thought you were trying to avoid. It would be sheer mayhem. Naturally, I am a product of my environment, so some things said in this thread evoked involuntary horror.

I have been doing this for years and dozens of Channel crossings, but I have actually learned some amazing new things this year since I finally installed AIS over the winter.

I used to have to rely on MARPA (very imprecise) and hand bearing compasses to work out a crossing situation, and because of the lack of precision of these methods I would take avoiding action -- if I were the stand-on vessel, as was usually the case -- when the CPA appeared to be less than a mile (or less than two miles if crossing ahead). It happened that I would be dodging fairly often. It also happened that I would get task overload, as we are often in crossing situations with three or even four ships at the same time, so your dodging calculation often has to consider more than one ship, which soon becomes unfeasible if you are working it out by hand.

Well, since I installed AIS I can now see a fairly exact calculation of his speed, course, bearing, and CPA, from much longer distances than I could with the old methods. Now I can see what I didn't have means to see before, which is that ships transiting the English Channel will take their action much further away than we think, often at 10 miles or more, and they don't mind passing much closer than I used to think acceptable -- seems to be 5 cables in most cases.

So this year, I have stopped dodging altogether, which I am sure is a great relief to the commercial helmsmen. Previously, there were always two or three ships, at least, on every transit, which I couldn't be sure were avoiding me, so requiring me to dodge. But now, with much more precise information about what the ships are doing, I have yet to observe a single one -- in four crossings -- which were not taking well calculated action based on my standing on and holding course and speed. It means that all or nearly all of my previous dodging actions were probably unnecessary and irritating to the commercial helmsmen, and were probably even dangerous from time to time, even though I did it as carefully as I could, and calculated these maneuvers conservatively.

On my last crossing, just last weekend, in heavy weather and moving at high speed in a heavy sea where dodging would have been really difficult (ever tacked in a F7?) -- we passed just 5 cables ahead of a large car carrier. Pete7 of this parish was with me. In the past, with such a situation developing, at two miles off, I would always have given up and tacked onto a reciprocal course to the ship to stop closing and let the ship go by. But the safety of that maneuver depends on being pretty sure about the course of the ship, and eyeballs alone don't always give you the right picture (it's easier at night because you can tell the aspect from the nav lights). If it turns out that you are crossing at an oblique angle, and you didn't quite understand the crossing angle, this maneuver can get you into real trouble, requiring another dodge, and if you're less than a mile off and still calculating avoiding actions, you've got a big problem.

So now with new tools, I can tell exactly how we are crossing and what the CPA will be. From far away, I can see how the ship is responding to my (inevitable while sailing) course and speed changes, so after a while -- and while still at a safe distance -- I can be sure that he sees me and is in control of the situation. Which means I can be sure that my job is to hold my course and speed as steady as possible and get across his path and out of the way. It is vastly much safer that way. AIS is really a killer app for this; I wish I had realized that earlier.
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Old 20-09-2013, 10:43   #187
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Re: What can happen when you cut off a ferry

A question keeps troubling me, maybe I could get some resolution on it please from those who support the very simplistic view of 'just get out of the way'?

A large, very fast, highly manouverable ferry is visible, it's daytime, at a dock approx 1nm away from a slow chugger.
The slow chugger is holding it's course, in daylight, the wheel is attended and the pilot has seen the stationary ferry.
I presume the chugger's not in stealthmode and is possible to be located visually.
The ferry begins its journey, ie. ceases being stationary and accelerates setting a course.
The chugger has already set and by accounts was maintaining, its course.
The ferry must be going much faster and coming from astern to run over the chugger in the manner described, in the time frame inferred if not explicitly stated.
The question that niggles me, as an owner of a fast boat and past owner of a chugger, is HOW the hell the chugger was supposed to actually evade the ferry?
My Avon could it, it's much faster than the ferry and way more nimble.
My chuggers could not do so well.
Even if I watched the ferry from the dock and realised at 1/2m it was on a collision course closing at 15-20kn there's very little time left for effective evasion at 5kn.
The ferry,from what the locals say here is 3 to 5 faster than the chugger and coming from astern, so for the advocates of 'just get out of the way', just how would you physically do that, [NB: accelerate to warp speed is not an option, nor is calling a towboat]
Please note:
This is not a Colregs question, I thought I understood them pretty well but as has been pointed out above there's many here to learn more from and I enjoy that.
Cheers,
Mac
Edit: Didn't see Ann T Cate's post quoting Dockhead whilst called away after starting this. Great Posts!
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Old 20-09-2013, 10:57   #188
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Re: What can happen when you cut off a ferry

[QUOTE=Dockhead;1344740]
Quote:
Originally Posted by Ann T. Cate View Post

I sail in the world's busiest shipping lane...
But of course you know I wasn't talking about your situation.

If I see A FERRY I'm going to stay out of its way.

If I see ten big ships I'm going to need a change of clothes.
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Old 20-09-2013, 11:03   #189
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Re: What can happen when you cut off a ferry

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Originally Posted by Wraith_Mac View Post
A question keeps troubling me, maybe I could get some resolution on it please from those who support the very simplistic view of 'just get out of the way'?

A large, very fast, highly manouverable ferry is visible, it's daytime, at a dock approx 1nm away from a slow chugger.
The slow chugger is holding it's course, in daylight, the wheel is attended and the pilot has seen the stationary ferry.
I presume the chugger's not in stealthmode and is possible to be located visually.
The ferry begins its journey, ie. ceases being stationary and accelerates setting a course.
The chugger has already set and by accounts was maintaining, its course.
The ferry must be going much faster and coming from astern to run over the chugger in the manner described, in the time frame inferred if not explicitly stated.
The question that niggles me, as an owner of a fast boat and past owner of a chugger, is HOW the hell the chugger was supposed to actually evade the ferry?
My Avon could it, it's much faster than the ferry and way more nimble.
My chuggers could not do so well.
Even if I watched the ferry from the dock and realised at 1/2m it was on a collision course closing at 15-20kn there's very little time left for effective evasion at 5kn.
The ferry,from what the locals say here is 3 to 5 faster than the chugger and coming from astern, so for the advocates of 'just get out of the way', just how would you physically do that, [NB: accelerate to warp speed is not an option, nor is calling a towboat]
Please note:
This is not a Colregs question, I thought I understood them pretty well but as has been pointed out above there's many here to learn more from and I enjoy that.
Cheers,
Mac
Edit: Didn't see Ann T Cate's post quoting Dockhead whilst called away after starting this. Great Posts!
I don't know what a "chugger" is, but 1) you don't wait until it's on top of you and 2) you move 90 degrees from its course. The ferry is fast; it will be on its way and you can return to where you wanted to go. I don't want to be in a situation where we have to decide who is the "stand on" vessel.

If there's TEN boats out there? If that had been my only option for sailing, I probably wouldn't have taken it up. I think that would have sucked all the joy out of it for me to have to run a field of targets like that while being a complete beginner.
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Old 20-09-2013, 11:29   #190
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Re: What can happen when you cut off a ferry

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Originally Posted by Rakuflames View Post
I don't know what a "chugger" is, .
Yet you still feel qualified to make a comment?
Head down, back away boys, head down back away!
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Old 20-09-2013, 11:50   #191
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Re: What can happen when you cut off a ferry

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I don't know what a "chugger" is
Running the gauntlet of chuggers on camden high street makes crossing between the Dover and Off Casquettes TSSs seem like a walk in the park...

(hmm..maybe that gag's a little too culture-specific for an international forum, but there is a segue back to the original issue of collision avoidance in a discussion about attempting to avoid people in the street...)
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Old 20-09-2013, 12:54   #192
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Originally Posted by Rakuflames View Post

I don't know what a "chugger" is, but 1) you don't wait until it's on top of you and 2) you move 90 degrees from its course.
That is not correct procedure. The on-watch should hail the overtaking vessel on VHF and ask their intentions. If the stand on vessel suddenly dodges 90 degrees it has a 50/50 chance of turning into her path. There is a reason it's called the stand on vessel.

As an aside to the other back and forth on this unfortunate situation I believe no one has enough information to know with certainty what caused this accident. The speculation as to cause is not really helping anyone in my view. The COLREG lessons are a nice side effect though.
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Old 20-09-2013, 13:11   #193
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Re: What can happen when you cut off a ferry

[QUOTE=Rakuflames;1344753]
Quote:
Originally Posted by Dockhead View Post

But of course you know I wasn't talking about your situation.

If I see A FERRY I'm going to stay out of its way.

If I see ten big ships I'm going to need a change of clothes.


Rakuflames, Point of order: With reference to your post #188, you attribute a statement to me that I didn't write. Dockhead did. Furthermore, I do not know that you weren't talking about any of my situations, nor if so, which one(s). Please refrain from attributing knowledge of yourself to me, who, not living inside you, cannot possibly know what you do or do not know.

As I see it, what leads to some of the acrimony here, is that when you write, it seems that you have not re-read what you have written to check whether it reflects what you really mean. Then, suddenly you are stuck in the position of defending opinions that aren't exactly what you meant. If you re-check your product for real world accuracy, before you post, I am sure you can improve your input for the newbies.

Although you labeled Dockhead's input as nit-picking, in fact the demonstration he made was of an example when there was nothing the sailboat could reasonably do but to put trust in the Colregs, and trust the professionals to do their job--which they did do, as shown by his subsequent post. It really, in my opinion, is important to understand about stand-on and give way. It isn't linguistic over-attention to detail; it's law....furthermore, specific knowledge and practice of Colregs saves lives and billions of dollars every year, due to collision avoidance. This is a big issue. It is irresponsible to misinform newbies about Colregs.

There's a huge irony here. The chap in Washington State, who was traveling in his home waters should have been more aware of the ferry, but being overtaken at 15 knots, might not have been able to physically change the direction of his boat enough to escape that collision. He is so fortunate to escape with his life. Living proof that s**t happens.
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Old 20-09-2013, 13:21   #194
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Re: What can happen when you cut off a ferry

So Rakuflames are you saying that the first incident with this bozo was your fault? Surely if you had been paying attention you could have gotten out of his way and not been hit just like the second encounter, correct?

I agree, it is your sailboat and you can change course if you want to, not always without violating the navigation rules, but you certainly can do it. Of course you are now putting yourself in the same ilk as the guy that hit you. I would prefer not to keep such company however. Please read rule 17, Action by stand on vessel.
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Old 20-09-2013, 13:37   #195
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Re: What can happen when you cut off a ferry

Quote:
Originally Posted by muttnik View Post
Running the gauntlet of chuggers on camden high street makes crossing between the Dover and Off Casquettes TSSs seem like a walk in the park...

(hmm..maybe that gag's a little too culture-specific for an international forum, but there is a segue back to the original issue of collision avoidance in a discussion about attempting to avoid people in the street...)
That's funny.
In this context though, slow boats go 'chug, chug, chug'
[figuratively speaking, not comparing Yanmars to Lister one lungers at all!]

AND fast boats go ROOAARRR!,
well maybe not well described hopefully well enough.
Cheers,
Mac
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