In praise of AIS

[prv]

The problem of "VHF-assisted collisions" is well known, and I've seen plenty of MCA guidance about avoiding it by sticking to the colregs instead of discussing the situation. It used to come up regularly in the CHIRP sheet that used to be included in the mags.

Agree with John though that these directions are mostly aimed at commercial shipping, where all concerned can see each other clearly on radar and/or visually, and the problem is establishing who's going which way round who. For a yacht, where the problem is instead being noticed at all, things may be rather different.

As an aside, vessels in Southampton Water constantly arrange passing each other in non-standard ways on ch12.

Pete

 

[wadget]

Likewise, without a reasonable explanation it seems a bit of a precious attitude, if they have somebody on watch whats the problem?

http://www.dft.gov.uk/mca/mgn167.pdf

Explains it quite well. Basicly if everyone is following the colregs there is no need to talk to each other.

 

[Koeketiene]

Likewise, without a reasonable explanation it seems a bit of a precious attitude, if they have somebody on watch whats the problem?

Crying 'wolf' too often?

Not too long ago, whilst crossing a TSS, I overheard a yacht 1NM ahead of us calling merchant shipping to inform them that they would pass by them - CPA 2NM - in 20 minutes time. Visibility was good at the time.
Why make that call?

Bridge officers could get fed up answering yachts, and ignore a true 'emergency'.

 

[PaulGooch]

http://www.dft.gov.uk/mca/mgn167.pdf

Explains it quite well. Basicly if everyone is following the colregs there is no need to talk to each other.

How do you think you'd fair in an accident investigation, after running down a small yacht, when it came to light the yacht had seen you on a collision course on his AIS, tried to avoid you, tried to call you on CH16, but you ignored the radio call ?

 

[wadget]

How do you think you'd fair in an accident investigation, after running down a small yacht, when it came to light the yacht had seen you on a collision course on his AIS, tried to avoid you, tried to call you on CH16, but you ignored the radio call ?

Pretty much the same as I would if I hit the yacht after an confusing discussion on vhf.

However if the yacht has AIS and a radar reflector and is showing the correct light I would have seen him and taken avoiding action.

 

[wadget]

As an aside, vessels in Southampton Water constantly arrange passing each other in non-standard ways on ch12.

Pete

Yes but that is generally with pilots on board and is being supervised by the VTS operators.

 

[FistralG]

In my experience it will tell you everything about the nearby traffic, at a glance - name, speed, course, rate of turn, and crucially - closest point of approach, time to CPA, and really importantly the orientation at CPA.

I have never used radar, but to have all this information and more (eg MMSI) instantly is a real stress-reliever.

Read for yourself.
http://www.vespermarine.co.uk/marine-safety-products/ais-watchmate-tx.html/#features

Edit - one huge advantage over radar is that it consumes almost no electricity - even when the transmit feature is switched on.

bbg thanks for the additional info. I've still not received a response from the OP (I guess he's got me on ignore)
The reason I asked is I've never had the opportunity to use AIS other than on marinetraffic.com and was interested to know why the OP thought it was so useful on this particular trip. We're potential collisions avoided? Or did it just help to alleviate the boredom of a poor weather crossing, being able to identify other boats in the vicinity?

 

[John Barry]

I would call a vessel to check that he had seen me on his radar. I'm not normally on boats with class b transponders and I'm aware of how radar invisible yachts can be, and in poor conditions they can be visually invisibly too.
Interestingly I was called up by a cargo ship about a month ago in the Western approaches. He was on his way to New York, and couldn't believe that we could be out there and not in trouble (we had about SW 30-35Kn). He ended saying he's rather be where he was than where we were.

 

[PaulGooch]

Pretty much the same as I would if I hit the yacht after an confusing discussion on vhf.

However if the yacht has AIS and a radar reflector and is showing the correct light I would have seen him and taken avoiding action.

Most small vessels that are fitted with AIS will be AIS receivers, so they won't help you spot them.

In an ideal World, everyone will see everyone else, sadly we don't live in an ideal World. I do find it a bit of a concern that there are bridge officers out there that routinely ignore calls on VHF though.

 

[wadget]

Most small vessels that are fitted with AIS will be AIS receivers, so they won't help you spot them.

In an ideal World, everyone will see everyone else, sadly we don't live in an ideal World. I do find it a bit of a concern that there are bridge officers out there that routinely ignore calls on VHF though.

You find it concerning that officers follow MCA advice?

 

[Talulah]

http://www.dft.gov.uk/mca/mgn167.pdf

Explains it quite well. Basicly if everyone is following the colregs there is no need to talk to each other.

I'm afraid I consider that attitude very naive.
That report is following a case in 1995.
The main butt of the problem was the time taken to identify the vessel to call when avoiding action could have been taken.
It is now possible with AIS to identify and call the ship with virtually no time wasted.

I certainly would not advocate routinely calling ships but given I now know who to call I would add it to my list of options to consider.
The nice thing about AIS is you can see much earlier if the vessel is already taking avoiding action and hence avoid adding to the confusion.
I make frequent visits cross-channel and would recommend fitting AIS before Radar every time.
I accept one is not a substitute for the other but for most people who only cross in relatively clear conditions they will find AIS far more useful IMHE.

Actually, it's about time the MCA updated that advice regarding the use of the VHF if they haven't already done so. As I said there has been more recent criticism for not using the VHF.

 

[Channel Ribs]

I make frequent visits cross-channel and would recommend fitting AIS before Radar every time. I accept one is not a substitute for the other but for most people who only cross in relatively clear conditions they will find AIS far more useful IMHE.

I absolutely agree with that statement, especially when you consider AIS is available for 100 pounds and up.

 

[wadget]

. As I said there has been more recent criticism for not using the VHF.

Could you point me to where as I have not seen these reports.

 

[Talulah]

Could you point me to where as I have not seen these reports.

I'll try and dig it out. Basically it was two ships in the Channel in clear conditions.
In the meantime have a read of this.
http://www.lawandsea.net/maritime/master_VHF_in_collision_avoidance.html

I think it sums it up very well. Problem is we know of collisions were VHF played a part. We don't know how many collisions have been avoided by the use of VHF.

 

[PaulGooch]

You find it concerning that officers follow MCA advice?

Can you point me to the MCA advice that tells bridge officers to ignore calls from other vessels on CH16 please ?

 

[Blue5]

Crying 'wolf' too often?

Not too long ago, whilst crossing a TSS, I overheard a yacht 1NM ahead of us calling merchant shipping to inform them that they would pass by them - CPA 2NM - in 20 minutes time. Visibility was good at the time.
Why make that call?

Bridge officers could get fed up answering yachts, and ignore a true 'emergency'.

Thanks, I have read the link, I note it was dated 2001 and was as a result of a case in 1995, presumably we have moved on now with AIS available on yachts to give the actual ships name and call sign so contact would be more "personal"

My radio contact earlier this year was as a result of a head on convergence that started with a five mile gap, boat coming towards me at 15kts and me hard on the wind at 6kts, I did not need AIS to see the problem so I eased the sheets and bore away to starboard only problem being that he altered course slightly to port. At that point with the gap rapidly closing and with AIS data I called him on 16, he acknowledged and altered course to starboard, now I do not know if he had seen me or not but I do not see sailing amongst big ships as a game of chicken and the later you leave a developing situation the more radical the action needed to remedy and more like hood of an accident.

Not much use in court telling Mrs NDH the other party was guilty but at least your late husband was following the colregs.

I still think it is a risky business telling officers to ignore calls from yachts, no I think it is criminal.

 

[BrianH]

Also please do not use the VHF to call ships for collision avoidance, as any well trained officer will ignore you, and the rest will probably struggle with english just making the situation worse.

It was only by calling this target passenger ferry by name on channel 16 that it immediately altered course to avoid me. At a closing speed of almost 40 knots and only 1nm away I had become very nervous once it had changed its bearing onto a collision course - VHF contact seemed the only strategy at the time because its heading was constantly varying between at least 5 degrees. It did not respond on VHF but the change of course occurred instantly after I had released the transmit button. The AIS report had given me the ship's name, which I used because I do not have MMSI data linked to the VHF.

 

[wadget]

Can you point me to the MCA advice that tells bridge officers to ignore calls from other vessels on CH16 please ?

It doesn't tell them to ignore calls on channel 16 but the advise is not to use VHF for collision avoidance, when I am called by another vessel and the call is clearly for collision avoidance purposes I will ignore it. Calls for any other purpose I will happily answer.

 

[Talulah]

Time to sit back. I can see some shovels coming out.

 

[Blue5]

Time to sit back. I can see some shovels coming out.

Its not worth replying, frightening......