Use of AIS in navigation

[Dictys]

I am a relative newcomer to the forum, so please bear with me.

Reading through the various threads, I am surprised by the amount of people who use or argue that AIS should or can be used for navigation or collision avoidance, as there is no provision in the COLREGs for use of AIS information decisions should be taken based mainly on visual and/or radar information.

Am I missing something? or is it all down to experience, cost or some other issue?

 

[RichardS]

AIS can really only be used for collision avoidance as that is it's primary purpose. I use for for entertainment and interest as well but that's a spin-off benefit.

As far as Colregs is concerned, there is a general imperative to use every means at one's disposal to avoid collisions at sea and AIS is, in many people's opinion, probably the best value collision avoidance system there is. Fitting it to larger ships is compulsory and some harbour authorities have introduced rules that all boats must install it, whatever their size.

It is inevitable that it will be in the next edition of ColRegs and I expect that in due course it will supercede radar as the primary electronic collision avoidance system on large vessels.

Richard

 

[[70521]]

As Richard says AIS is pretty new the COLREGS will catch up.

I like to see where people I've bumped into on my travels currently are. Ideal entertainment on a cold, wet winter's night seeing the signal from friends somewhere hot and sunny.

 

[prv]

I like to see where people I've bumped into on my travels currently are.

That got a smile in a thread about collisions

Pete

 

[Bobc]

I find AIS useful to see what's about (ships mid-channel etc.), and I can find out what they are and what course and speed they have, and it also gives me a name should I need to call them up. I then use No.1 eyeball and common sense to work out whether to go in front or behind.

 

[Minchsailor]

I think it is a useful addition to the armoury for deciding if a collision situation is likely to develop. Not so sure that it essential as some think it is.

Even though I sail in waters which are relatively empty, I have found that a surfeit of AIS signals on the plotter screen can hide important information. For that reason, most of the time I have my AIS on (and I seldom use it), I have the transmit function turned off.

 

[dk]

AIS is another v useful tool in the toolbox, so long as you remember it's not mandatory to fit a transponder so many leisure craft won't be transmitting. Also, some boats, especially fishing boats, turn them off when they don't want other folk knowing where they are!

 

[pyrojames]

I find AIS very useful in establishing whether the bearing to another vessel is changing. Much like using a hand bearing compass but without the vagueries of trying to juggle a compass on deck. Obviously the CPA can is useful but it can be severely conpromised by speed and course fluctuations in a sailing vessel.

 

[BrianH]

AIS can really only be used for collision avoidance as that is it's primary purpose.

That may be so for us, now, but interestingly, as a fellow forumite who has been an IMO delegate informed during a previous, long-running AIS thread, the prime reason for AIS technology, was as a VTS maritime security tool. Only in the final states of implementation of the SOLAS chapter V, regulation 19 in 2001, was the bonus of collision avoidance formally recognised and promoted, but it wasn't the driver.

 

[laika]

Am I missing something?

Rule 5?

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 or the risk of collision

 

[knuterikt]

That may be so for us, now, but interestingly, as a fellow forumite who has been an IMO delegate informed during a previous, long-running AIS thread, the prime reason for AIS technology, was as a VTS maritime security tool. Only in the final states of implementation of the SOLAS chapter V, regulation 19 in 2001, was the bonus of collision avoidance formally recognised and promoted, but it wasn't the driver.

And the the purpose of VTS is to avoid collisions..
The fact that both VTS and ships officers can use it just makes it a better tool.

 

[johnalison]

The question of using AIS for navigation suggests that I might wish to obtain a bearing from a fixed source and navigate from that. This sounds rather entertaining and I must try it some time, before moving on to navigating from moving targets.

 

[pagoda]

Rule 5?

I was on the bridge of a passenger ferry a year or so back (invited!) I quizzed the guys on watch about AIS. They said they transmit - as the law requires but they do not watch it. They use radar and visuals pretty exclusively. I think it's perhaps a function of their age/training.? Maybe not - another friend who is 1st Officer on a Cunard cruise ship said much the same, Radar and Mk 1 eyeballs...
I think the value of a good radar reflector is not to be under-estimated! Even one of the enhanced return versions. Until AIS gets into the crew training regime and mainstream don't expect too much. Anybody on a big ship is likely to want to filter out the <10> metre clutter in any case? There are places with far too much AIS in use. At least in Germany there are newer rules to prevent transmission unless under way, so the multiple alarms passing marinas won't happen in future. I hope!

 

[laika]

I am surprised by the amount of people who use or argue that AIS should or can be used for navigation or collision avoidance, as there is no provision in the COLREGs for use of AIS information

I was on the bridge of a passenger ferry a year or so back (invited!) I quizzed the guys on watch about AIS. They said they transmit - as the law requires but they do not watch it.

I think the OP's question was not about whether it is used in preference to radar by bridge crews but rather whether there was provision in the COLREGS to allow for its use.

Hugo : Tous les moyens ne sont pas bons.
Hoederer : Tous les moyens sont bons lorsqu'ils sont efficaces.

I can't mention rule 5 without channeling sartre by way of malcolm X...

 

[PilotWolf]

The question of using AIS for navigation suggests that I might wish to obtain a bearing from a fixed source and navigate from that. This sounds rather entertaining and I must try it some time, before moving on to navigating from moving targets.

It can be done if you use a short based station. I can't remember any offhand in the UK as it's been a while but I know of a few around Southern California.

W.

 

[LadyInBed]

I think the OP's question was not about whether it is used in preference to radar by bridge crews but rather whether there was provision in the COLREGS to allow for its use.

He didn't mention COLREGS or collision avoidance either, he asked about its use in NAVIGATION!
I believe that Lighthouses are being fitted with AIS transceivers and some bouys, so you could argue that they can be used for navigation!

 

[prv]

He didn't mention COLREGS or collision avoidance either, he asked about its use in NAVIGATION!
I believe that Lighthouses are being fitted with AIS transceivers and some bouys, so you could argue that they can be used for navigation!

And some buoys (especially off the French coast) have been removed altogether and replaced by AIS broadcasts from the shore

Pete

 

[Bru]

The question of using AIS for navigation suggests that I might wish to obtain a bearing from a fixed source and navigate from that. This sounds rather entertaining and I must try it some time, before moving on to navigating from moving targets.

It would be incredibly foolish to navigate from a moving target (we won't mention the occasion when I eyeballed a useful white splodge on the shore to steer towards only to find myself wandering off course as the driver of the white lorry finished his lunch and set off on the road again!). However ...

He didn't mention COLREGS or collision avoidance either, he asked about its use in NAVIGATION!
I believe that Lighthouses are being fitted with AIS transceivers and some bouys, so you could argue that they can be used for navigation!

Believe, believe! It's more a case of "have been fitted" as opposed to "are being fitted" in the case of lighthouses (at least in the busier areas of the UK coast). And most major navigation marks are fitted with AIS. But it gets more interesting ...

And some buoys (especially off the French coast) have been removed altogether and replaced by AIS broadcasts from the shore

Yup. VATONs (Virtual Aids to Navigation). Mark my words, we'll see a trend over the coming years to do away with expensive to install and maintain physical buoys and use VAToNs instead wherever the authorities feel they can get away with it.

 

[SimonFa]

It would be incredibly foolish to navigate from a moving target (we won't mention the occasion when I eyeballed a useful white splodge on the shore to steer towards only to find myself wandering off course as the driver of the white lorry finished his lunch and set off on the road again!).

HaHa, I did something similar as a young soldier on a map reading exercise in Northumberland. It was dusk and I took a bearing on what I thought was a feature on the skyline of the hill we were walking up. Turned out to be a flock of sheep.

 

[Lon nan Gruagach]

The question of using AIS for navigation suggests that I might wish to obtain a bearing from a fixed source and navigate from that. This sounds rather entertaining and I must try it some time, before moving on to navigating from moving targets.

But but but......
The only way your AIS display can determine a bearing from any target is by knowing where you are (almost exclusively by GPS). It would be a remarkably obtuse installation that didnt present your current position and bearing to any waypoint of your choice.

pre edit add:
Although harbour entrances often(?) specify an approach bearing, so to save entering a waypoint into your navigation system, bearing to a fixed (possibly virtual) AIS target would make life that wee bit simpler.