Over-Reliance on AIS -- Collision off Dungeness

[Dockhead]

Originally Posted by Simonsays

the best way to distinguish those that have seen you from those who have not is making contact.
if they are not responsive on the radio, seriously start considering options.
if they respond, it already has started to solve the situation.

I agree with that based on long experience, BUT -- only after you have done a competent job of determining there really is a risk of collision, and you are not being lazy and trying to save yourself that work by calling. If you have AIS, it's pretty straightforward, but if not you need to have a skillful hand with HBC or radar and NOT just guess by looking. You will really annoy a busy commercial watchstander if he has already made a good correction and if you had any skill, you could determine the 1 mile CPA, but instead of bothering to figure that out, you are distracting him from his work.

The MCA actually discourages using the radio in collision avoidance, but I have come around to your view. If I'm supposed to be standing on, and there is a ship closing on me with CPA of less than 1 mile (typical standing orders minimum CPA in open waters), and we are only 5 or 6 miles apart, then I will call and ask intentions. If the watchstander answers, he will typically say one of two things:

1. "I see you, and I'm altering course to starboard to give you more room"

or

2. "I don't see you" or "what's the problem".

In case of 1, I thank him and continue standing on.

In case of 2, I tell the watchstander that I am turning to starboard (or whatever) to pass x distance behind him (or whatever), and I ask him to PLEASE hold HIS course and speed.


The purpose of all of this, and all the collision avoidance procedures in the COLREGS, is to avoid having both vessels maneuvering at one time. For a safe crossing, ONE vessel has to play the ACTIVE part, and the other vessel has to hold its course and speed, so that the active vessel's solution of the crossing will be valid.

This is why it is SO HARMFUL to willy nilly change course and speed, if you're supposed to be standing on, and the other vessel is relying on that.

There are two really cardinal sins made by WAFIs:

1. Bad watchkeeping and oblivious to traffic and collision risks.

2. Failing to stand on during that phase of a crossing, when standing on is required.

I discussed this a lot with commercial mariners, and one thing which surprised me was that they almost all told me that they MUCH PREFER TO DEAL WITH SIN #1, than Sin #2. Because the WAFI who doesn't even see the ship, will not make any sudden moves, and they can deal with that. One of the genius things about the COLREGS is that it only takes one vessel following the Rules, for collisions to be successfully avoided.

Sin #2 -- failing to stand on when required -- is the worst -- as commercial mariners told me over and over again -- because sudden maneuvers, especially uninformed maneuvers by WAFIs who are not capable of plotting a crossing and just eyeball it -- invalidate their solutions and create collision risks which can even be unavoidable, depending on the distance.


Many commercial mariners told me that they had such bad experiences with WAFIs that they try to maneuver very far ahead -- as much as 15 miles -- and to create a CPA of more than the usual 1 mile, in fact, two or three miles, and to pass astern of the WAFI, so that no matter what stupid maneuver the WAFI makes, he can't possibly screw up the crossing. Meaning even if he makes a 180 to sail right into the path of the ship, he won't be going fast enough to get there. We are not even aware of those maneuvers, because they take place long before we are even aware the ship is out there.

That's how bad we are at collision avoidance, and why I bore people with all this preaching about it. The usual WAFI attitude about collision avoidance is arrogant ignorance, an attitude I have declared a personal little war on.

If Nigel is still around, I'm sure he'll back me up on all of this, although he will chide me for being boring, I guess.

[Polux]

Originally Posted by Dockhead

...

Don't take our word for it (as if there were any chance of that ); ask around yourself, think about it, work on it. Collision avoidance is a science, which demands a certain amount of learning and work, to achieve even a minimal level of competence. One thing for sure -- if you think you can just look up, recognize a risk of collision, and dart out of the way, as many WAFIs do -- you are definitely doing it wrong.

Not sure what you mean saying with this. Do you mean that you cannot recognize the risk of collision using only your eyes and get out of the way? If that is what you want to say you are obviously wrong.

It was made that way successfully for centuries and if it was not possible to do so then AIS and Radar with MARPA would have to be mandatory to all sailboats, no matter the size.

Yes, I agree that it is needed a minimum level of competence, to know the rules and to know how to proceed. That is why I think that all should have a formal education regarding that (and not only) complemented with practical training.

Regarding asking around I don't need too. As I have told you I have several licenses taken under the apprenticeship of merchant ship captains and I proceed as I have been told by them regarding what they consider to be the safest option.

I have also decades of experience regarding that and I have always done that successfully. The only difference is that on the first years I needed to make bigger detours to make sure I was out of the way.

[jackdale]

Here is a situation that developed a couple days out of Cape Town in September. We were the give-way vessel.

We were contacted, by name, by the fishing vessel Hai Lim. Their skipper was also a sailor.
They were going to start shooting long lines at 0200 local time in our direction.
We monitored the situation with AIS.
They passed 4 miles astern at 0335 local time.

No risk of collision actually occurred, but we were a little more attentive

In my mind that was a great use of AIS and VHF by all involved.

[jackdale]

Originally Posted by Polux

Not sure what you mean saying with this. Do you mean that you cannot recognize the risk of collision using only your eyes and get out of the way? If that is what you want to say you are obviously wrong.

I think Dockhead is indicating that determine a risk of collision with the Mark I eyeball takes a little time to take a series of hand-bearing compass readings.

One glance will not tell you if a risk of collision exists.

[CarlF]

I believe both vessels in the collision were in violation of COLREGS 5 -

Lookout : Every vessel shall at all times maintain a proper look-out by sight and hearing as well as by all available means appropriate in the prevailing circumstances and conditions so as to make a full appraisal of the situation and of the risk of collision.

An AIS transponder certainly seems within "all available means appropriate" in those crowded waters. Among other things, it far more likely that the Stand On vessel will be identified.

If both vessels in the collision had AIS transponders, does anyone doubt that the collision would have been avoided?

It's no secret that COLREGS is not updated frequently. Who today would signal distress by flying the COLREGS approve November Charlie flags or light a fire on their deck?

And the observation that some vessels don't use AIS is beside the point. Not every boat uses radar but no one uses that as an argument against radar reflectors.

.

[jackdale]

Originally Posted by CarlF

Not every boat uses radar but no one uses that as an argument against radar reflectors.

.

Radar reflectors are a requirement under Rule 40.

[donradcliffe]

After seeing this, would you believe that the professional ships crews know the COLREGS and how to use their AIS??

The Dutch freighter Flinterstar collided with VLGC AL ORAIQ early in the morning on Tuesday

Would you bet your life on it, like Dockhead wants us to do??

[leftbrainstuff]

Originally Posted by Dockhead

This is a sad, but not unexpected story:

https://www.gov.uk/maib-reports/coll...ast-of-england


The bridge of a fast moving bulker did not bother to watch their radar or use ARPA. In the Dover Strait!! Encountered a small tug towing a barge and not broadcasting AIS. Saw it apparently only already in close quarters, turned to port, collided with the tow, snagged the towline, and would probably have killed the crew of the tug had the tow line not parted.

A lesson for all of us to keep a sharp watch on radar and do NOT assume that every target of interest must be broadcasting AIS. I have caught myself leaning too hard on AIS and thought how easy something like this would be to happen.

AIS wont tell you if a target is towing or being towed.

AIDs to navigation. These aids dont come with a warranty.

Situational awareness is something only humans with eyes, ears, smell and touch can posess.

Sent from my SM-N900T using Cruisers Sailing Forum mobile app

[MarkJ]

Originally Posted by donradcliffe

Would you bet your life on it, like Dockhead wants us to do??

Don, don't be naughty. Of course he's not getting his life on it.

The stand on vessel has the ability to take evasive action till quite late.

I certainly do make plans in case the ships crew are asleep on the bridge... but not till quite close and after I have tried to contact via VHF

[leftbrainstuff]

Originally Posted by MarkJ

Don, don't be naughty. Of course he's not getting his life on it.

The stand on vessel has the ability to take evasive action till quite late.

I certainly do make plans in case the ships crew are asleep on the bridge... but not till quite close and after I have tried to contact via VHF

The standon vessel is a great concept but in the real world I put my trust in the laws of physics, nature and dumbasses.

I abide by the first, I respect the second and I like to keep as far away from the third using the first as I can.



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[donradcliffe]

Originally Posted by Dockhead

Edit: One should also not assume that because you are broadcasting "B" class AIS, that you will see the ship, before the ship sees you. I believe someone posted something like that above. A well-run ship's bridge will be using S-Band radar in open water, and ARPA, and unlike the case described in the original post, will not be relying on AIS. These radars are incomparably more powerful than ours, and have antennas mounted high on the superstructure. They will often see you from 20 miles off.

Let me give you some real life examples:

One night I'm headed to Bermuda from the BVI, and my AIS (receiver only) says that there is a ship 60 miles away which will cross me with a CPA of 0.1 miles. I hit the autopilot buttons and make a 2 degree course change--now the CPA is 2 miles. Sure enough, 4 hours later the ship crosses 2 miles ahead of me. I'm violating your interpretation of the Colregs, but everyone is happy, and I don't have to depend on their watchkeeping skills.

In the pre-AIS days I would get into a situation where I was within 5 miles of a ship and am concerned about the risk of a collision. I start calling on the radio, and most times I would be ignored, but in the few times they answered, they said they could not seem me on their radar until I told them where to look.

Finally, yes, you will see their Class A AIS before they see your Class B. That is just physics--same antennas, lower power.

[Dockhead]

Originally Posted by Polux

Not sure what you mean saying with this. Do you mean that you cannot recognize the risk of collision using only your eyes and get out of the way? If that is what you want to say you are obviously wrong.

No indeed -- this is absolutely true. You cannot participate in traffic where other vessels, moving a double your speed or more, and using radar and AIS, with eyeballs alone, and take any meaningful action. You are mere flotsam, entirely reliant on the skill of the other mariners. You cannot distinguish a collision course from a 1 mile CPA until it's too late to do anything about it, with your bare eyes, when you are dealing with a speed difference with a commercial ship. Try it some time, comparing your eyeballs, with what AIS tells you, and you will see how true this is. At the distance most ships are making their decisions about how to cross with you, you can't even tell their aspect, with your bare eyes.

Whether it was "made that way successfully for centuries" is debatable. Uncountable ships have been destroyed in collisions over the centuries, which lead to constant efforts to improve the technology, techniques, and rules for collision avoidance. If you are happy to do it the way it was done in the 18th century -- well, I guess that's up to you.

Originally Posted by Polux

I have also decades of experience regarding that and I have always done that successfully. The only difference is that on the first years I needed to make bigger detours to make sure I was out of the way.

I also knew a German guy once who used to race across busy highways, and thought that because he had never been hit, that this fact was proof that his technique was good. Exactly the same argument which you are making here

You have "done it successfully" only because ships you encountered treated you as a WAFI, and made sure to maneuver in a way where you could not create any danger to them, or to yourself. You didn't even notice that they were doing it.

[nigel1]

Originally Posted by donradcliffe

Let me give you some real life examples:

One night I'm headed to Bermuda from the BVI, and my AIS (receiver only) says that there is a ship 60 miles away which will cross me with a CPA of 0.1 miles. I hit the autopilot buttons and make a 2 degree course change--now the CPA is 2 miles. Sure enough, 4 hours later the ship crosses 2 miles ahead of me. I'm violating your interpretation of the Colregs, but everyone is happy, and I don't have to depend on their watchkeeping skills.

Don, in that situation, at 60 nm out, risk of collision would not be considered to exist, and colregs would not apply.
By making you 2 degree alteration at that distance, you have made everyone happy, and not flouted any colregs

[Polux]

Originally Posted by donradcliffe

After seeing this, would you believe that the professional ships crews know the COLREGS and how to use their AIS??

The Dutch freighter Flinterstar collided with VLGC AL ORAIQ early in the morning on Tuesday

Would you bet your life on it, like Dockhead wants us to do??

This is absolutely incredible:

https://www.youtube.com/watch?v=IknycXF_lSI

It makes me remember me being rammed at anchor at full blast by a big motorboat at full blast astern, not once, but twice.

A British skipper that witnessed the weird accident asked me "What have you done to his wife?" It seems on purpose.

[rognvald]

Originally Posted by leftbrainstuff

AIS wont tell you if a target is towing or being towed.

AIDs to navigation. These aids dont come with a warranty.

Situational awareness is something only humans with eyes, ears, smell and touch can posess.

Sent from my SM-N900T using Cruisers Sailing Forum mobile app

Leftie,
Your above remarks and your subsequent post #115 are the crux to good seamanship and navigation. There is no substitute for "situational awareness." Good posts! Very well said!