AIS. Lies & Misconceptions

[Peppermint]

I'm getting a vibe about AIS that shows a fundamental misunderstanding of what it's all about. To many people are using AIS & Radar in the same breath

An add in the March 2005 YM states

AIS Radar
" All vessels over 300 tonnes and all passenger vessels must now carry an AIS transponder."

Well thats simply wrong. Vessels up to 500 tonnes that don't go foreign are exempt. Implimentation for foreign going vessels is not going to be completed until 1st of July 2008. Warships don't use them. Many ships turn them off or suffer malfunctions.

The implication from this advert is that AIS is some sort of radar substitute. It's not. It's a commercial/security/administration system that even when it is fully implimented will offer cold comfort to yachtsmen on a foggy night in the channel.

 

[Gordonmc]

Even if a commercial vessel has AIS installed, it might not be switched on. For reasons of their own some operators don't like the position and track of their cargoes being in the even more public domain. So that merchantman on your screen might not be the one bearing down on your port quarter!

 

[Ifraser]

Thank god I'm not the only one to think like that. To think that AIS is any kind of RADAR substitute is foolhardy in the extreme and the companies marketing them as such are being grossly negligent IMHO of course!! It may have its uses and may be a good system but NEVER a RADAR substitute.....

 

[mjf]

Re: AIS - great!

Like all this stuff it's an aid.

You are correct on the security implications - in fact I read an article last week that suggested that airlines would pick up the AIS signals in the trans Pac / atlantic routes and feed the info back to the CIA etc in the states. That way the USA could monitor traffic in 'their' oceans 24/7!

Where the AIS is very useful is when you have a target on radar or visually and need to communicate but alas cannot see its name. By calling it by name you can quickly detemine if indeed its the ship you think it is and pass over your intentions or make a request etc etc.


I think its excellent, its good also for getting a traffic overview using the web site page.

 

[Mirelle]

Provided that the transponder has been updated

It is amazing how many ships are going in the wrong direction in the English Channel according to their AIS transponders - simply because the OOW has forgotten to update them after discharge.

I thought that the US was proposing to use the AMVER system, not AIS. This is contentious because AMVER is a safety system.

 

[mjf]

Re: Provided that the transponder has been updated

No AMVER too - it might become mandatory, rather than a volunteer SAR thing

 

[andrewbarker]

Re: AIS. Lies & Misconceptions

It's currently picking up a large number of vessels carrying copper powder in bulk heading for the UK south coast.
Also, further out several vessels carrying bulk antifoul removal products can be seen. What can this mean?

 

[mjf]

Re: AIS. Lies & Misconceptions

Hells bells - are you saying that Barnacles might be able to receive AIS transmissions?

 

[Peppermint]

Re: AIS - hype

I'd say AIS is as useful as a fishnet lifejacket and just as dangerous. It promises so much more than it delivers.

In thirty years & 70k or more of sailing offshore I've never need to call a ship.

 

[mjf]

Re: AIS - hype

Well I have of numberous occassions to simply determine what are 'his' or to advise my intentions.

Last time a vessel was NUC in Gib Straits - was able to call vessel by name whilst still 5/6 miles off and advise would pass clear and then proceed into Algeciras bay.

Saved any hassle to him or us should he suddenly restore power and get underway just as we passed etc.

 

[Mirelle]

Re: Provided that the transponder has been updated

I really dislike the idea of a voluntary SAR system, which depends on the goodwill of seamen, being called in to aid President Bush's "War on Terror".

Since the merchant seamen who operate AMVER are not now allowed ashore in the USA, by virtue of the same "War on Terror", their enthusiasm for AMVER may dwindle!

 

[martinwoolwich]

I'm one of those that has AIS and use it all the time. I have to agree with Tom. It's no substitute for RADAR and never was intended to be. I use it 'cause I'm sometimes interested in information on a vessel such as it's name, cargo, where it came from, where it's going, how fast etc. (great for checking on the speed of the cats coming out of the Channel Islands!.

As an aid to navigation and ship safety I give it 5 out of 10 but as a fun thing to have on board 10 out of 10 and you never know, one day I might actually want to talk to someone and the publication of the MMSI could be useful (hasn't happened yet mind)

 

[Gludy]

Re: AIS. Lies & Misconceptions

I think that about sums up the use of AIS.
I was going to get one then found that Raymarine are bringing out a software update and a little receiver so that you will get the AIS on your chartp;otter/radar screen..... so I decide to wait for that.

 

[Jack100]

Re: AIS. Lies & Misconceptions

I agree, there are misconceptions about AIS, especially when some products are even being marketed as 'AIS Radar'. Ships should only have the system switched off 'when there are reasonable grounds' such as threat of piracy, but the fact that it 'could be' switched off makes the picture ever more incomplete.

When the system is integrated with ECDIS or Radar/ARPA it can prove very worthwhile, especially for positively identifying vessels. Minimum Keyboard Display units are often hard to digest. The system could also become congested, especially in areas of high marine activity, such as the Solent, if all recreation craft had to have it.

One benefit would be that it would (should) show large merchant ships who are not visible by eye or by radar, that is to say, around headlands for example. This is a clear benefit of the system in busy areas.

The system will also provide steadier and quicker vectors of targets than Radar can, this is because of the direct link with AIS and the ships compass, usualy gyro. This would make it clearer of any alterations of course in a collision situation. However the infomation transmitted is the responsibility of that ship, thus a certain amount of reliance is placed on the other vessels operating equipment. .

AIS will also provide the user with 'Navigation Status' of vessels in the vicinity. This will mean that 'Not Under Command' vessels can be established at a much greater range than seeing day / night signals, thus allowing more time to assess the situation.

All IMHO of course.

There are some misconceptions, but at the same time, there are benefits to it.

 

[rickp]

Re: AIS. Lies & Misconceptions

Yes - it will be useful when you can see it alongside the ARPA data. Of course, the temptation will be to *replace* the ARPA data with the AIS data which is where issues may arrise.

Rick

 

[Mike_Martin]

Re: AIS - great!

Also if it's a SOLAS or "Code" vessel you're calling, you can use its MMSI to make a ship to ship call.

Just a thought.

Mike

 

[Mike_Martin]

Had exactly the same misgivings at the London Boat Show but it's MCA's call on how these people market to the Pleasure Boat world really.

Mike