The Other Side of AIS...this deserves a thread of its own

[dt4134]

Remember, the transponder does identify the vessel as a sail craft. I'm sure a prudent OOW would take the option that a sail craft was under sail and therefore give it a sufficiently wide berth.
QUOTE]

But PoB was overtaking vessel so sail was irrelevent. The OOW simply didn't see them, partly because he was wearing reactolight glasses. Ouzo couldn't get out of the way as they didn't know which side PoB was going to pass (and remember in the scenario that MAIB presented it would've looked to Ouzo's crew that PoB was going to pass one side or the other until very late in the sequence). They wouldn't have been able to conclude they hadn't been seen until very late.

Any AIS information that Ouzo would've received had they had AIS would've contained out of date information regarding the rate of turn. Only if the AIS info had included the intended new course would they have had a chance to work out what was happening and I don't believe it has that.

Any AIS info Ouzo might have transmitted would not have been seen by the OOW because as the MAIB points out it wasn't integrated with the radar display. He'd have had to make a concious effort to walk off and check it.

So I still hold with the view that AIS would've made no difference.

 

[Shorn100]

dt4134
I agree with you that since the alleged vessel did not have an AIS receiver it would not have made any difference if the Ouzo had been fitted with a Class B. That was not my point.

I said... 'if the Ouzo had a class B transponder and if the vessel with which it had a close encounter had had a AIS receiver would it have altered its course to make sure it didn't run quite so close.'

My point is there would have been no close encounter if both craft have had the appropriate AIS equipment since the larger vessel would have seen the smaller vessel and changed course to stay clear. In other words AIS would have saved the day.

 

[dt4134]

dt4134
I agree with you that since the alleged vessel did not have an AIS receiver it would not have made any difference if the Ouzo had been fitted with a Class B. That was not my point.

I said... 'if the Ouzo had a class B transponder and if the vessel with which it had a close encounter had had a AIS receiver would it have altered its course to make sure it didn't run quite so close.'

My point is there would have been no close encounter if both craft have had the appropriate AIS equipment since the larger vessel would have seen the smaller vessel and changed course to stay clear. In other words AIS would have saved the day.

Agreed. But a collision may well have been avoided if PoB was keeping a proper lookout (i.e. OOW not wearing photo-chromatic lenses and not having sent the lookout off to do other duties).

It may well have been avoided if Ouzo had had a brighter nav light.

It may well have been avoided if Ouzo had had an active radar transponder.

It may well have been avoided if PoB had made a change of course in a way that was obvious to other vessels as per the ColRegs.

It may well have been avoided if the OOW had understood his ship well enough to be able to use more than 1 degree of helm to take avoiding action.

In other words it was an accident that had many causes.

I still don't believe that AIS is regularly used for collision avoidance on commercial vessels. Some small craft skippers may want to fit it and it may be a useful aid to collision avoidance but IMHO it is still one that is well down the pecking order.

 

[BrianH]

I would say that the collison would very likely not have happened if the vessels involved had been equipped with AIS.

As the MAIB investigation concluded, the most probable cause of the Ouzo foundering was a close encounter with the Pride of Bilbao.

If you mean IF the Ouzo had a transponder and IF the Pride of Bilbao had a fully-fledged AIS-ECDIS system then it is fairly obvious there would have been an infinitely better chance that the tragedy would have been prevented.

The Pride of Bilbao was equipped with AIS - it had to be to comply with SOLAS regulations - the report did not specify what (another open question), only that it did not overlay to the radar screen, which was the navigation tool being monitored at that time by the OOW. We can speculate that it may have been the basic MKD (Minimum Keyboard and Display) device - enough to comply with the SOLAS requirement. But of course, in the absence of hard information, that is pure speculation.

With respect to the MKD equipment, the following is from 'The Pilot', the magazine of the United Kingdom Maritime Pilots' Association, published close to the time of the Ouzo loss.

"With respect to the type of equipment installed, the overwhelming majority of vessels are fitted with the minimum required to comply with carriage regulations! These are small alpha numeric displays which at the absolute basic level have to display at least three targets. I have seen such minimal three line units on ships and for all practical purposes they are totally useless. Other systems cram a list of many targets into the small display (typically 9cm x 12cm) which renders them illegible and again these are totally useless.​

 

[BrianH]

It may well have been avoided if PoB had made a change of course in a way that was obvious to other vessels as per the ColRegs.

If I remember correctly, it was during the trial of the Pride of Bilbao first officer that the revelation surfaced that the shallow turn effected by the joystick steering control was to not disturb passengers so late at night rather than by a correct shorter one.

I believe this may have been a deadly factor for the Ouzo watch-keeper and could have contributed to the probable collision. However, as you point out, there were a host of other factors that escalated the risk.

I still don't believe that AIS is regularly used for collision avoidance on commercial vessels. Some small craft skippers may want to fit it and it may be a useful aid to collision avoidance but IMHO it is still one that is well down the pecking order.

Agreed, which is why I prefer to keep to my AIS receiver only and take the responsibility for avoiding the threats. Such as the screenshot below when I crossed the Gulf of Trieste this year. I decided that a CPA of 143m was cutting it too fine and rolled the headsail to slow down.

 

[NOHOH]

Maybe I`m missing Something.......

.......but, apart from information about a ship`s name, telephone number, and its bra size...What information does AIS give me that I`m not already getting with radar and MARPA? For those not familiar with MARPA its a facility with radar where you can track ANY object on the screen and you get SPEED, TRACK ,CPA,CTA.
What you get with AIS are ONLY THE OBJECTS WHO ARE TRANSMITTING THIS INFORMATION and NOT any of the objects that aren`t.
To my mind, there is a danger, not of not seeing the wood for the trees, but of not seeing the trees for the wood..and hence its a distraction .
Also, I never do anything wrong, so I don`t need any special monitoring or controlling...so ...is it worth paying out between 200 and 500 quid to have this AIS stuff onboard.

 

[BrianH]

.......but, apart from information about a ship`s name, telephone number, and its bra size...What information does AIS give me that I`m not already getting with radar and MARPA?
... is it worth paying out between 200 and 500 quid to have this AIS stuff onboard.

Is it worth paying out more than double to have radar on board? My AIS receiver cost $200 seven years ago, they are cheaper now.

I'll answer my own question. Yes, it probably is if you sail where there is often fog, such as the UK. But more importantly, if you can support the power requirements. I prefer not to try.

The MMSI data is useful to directly call any ship with DSC VHF - integrated units now do that automatically if required.

AIS vs radar - they are complementary. Here is an example where AIS reports a target that radar would not pick up due to the high land between us that would shield the higher frequencies involved (my boat is the large red arrow). No problem in this example but consider a closer constellation with converging courses, when AIS would give warning CPA and TCPA. Radar wouldn't see it. You'll note that none of the targets provide name and bra size - that's because they are all Class B transmissions, which my software is too old to decode. No problem for the dangerous big stuff with Class A, providing the non-simultaneous dual channel receiver has long enough to wait for the next static data sentence if it misses one.

 

[chuzzlewit]

Nanny state

Hi VO5
Can I just get it clear on what you mean when you say Nanny State?

Is the nanny state the one which brought in laws to protect drivers by insisting on sea belts being worn?

Is the nanny state the one which brought in laws to protect motorcyclists from brain damage and death by bringing in laws insisting on crash helmets?

Is the nanny state the one which brought in laws to redice my chances of dying from cancer (and smelling like an ash tray) due to others smoking around me.

Is the nanny state the one which brought in a National Health Service to make sure nobody in the UK needs to go without healthcare?

Is the nanny state the one which brought in social security so that those who unfortuante enough to become unemployed have sufficient funds to eat?

Is the nanny state the one which brought disability allowances for those who are disabled don't have to live as beggars?

Is the nanny state the one which provides armed services to protect us from those that wish to harm us?

Is the nanny state the one which has a controlled airspace to ensure aircraft don't crash into each other?

Is the nanny state the one which brought in speed limits on the roads to reduce the chances of those travelling at excessive speed from running you over?

Is the nanny state the one which brought in parking restrictions so that our roads are safer?

Is the nanny state the one which brought in a minimum wage to prevent employers from abusing employees?

Is the nanny state the one which brought in health and safety laws to protect employees from being forced to use unsafe equipment?

Is the nanny state the one which banned dangerous substances such as asbestos?

Is the nanny state the one which provides emergency services such as police, ambulance, fire and coastguard to help us in our moments of distress?

Is the nanny state the one which has a secret service constantly protecting us from terrorists?

Is the nanny state the one which provides protection for the low tax haven called Gibralter?

Do you mean that Nanny State? You know, the one that makes living in the UK or a UK dependency worth while?

It's not perfect but I quite like it. In fact, I'm proud to be living in what has to be one of the best countries in the World. But, of course, you still have you freedom to leave and live somewhere that doesn't want to look after its citizens.

Shorn

Quite right: I'm all in favour of humane government.

 

[NOHOH]

Hmmmmm

Is it worth paying out more than double to have radar on board? My AIS receiver cost $200 seven years ago, they are cheaper now.

]

If the question is `would having AIS be better than having nothing`....then you`re absolutely right. The example you give with the chart, however, is entirely unconvincing. Approaching a situation like that (even if I had a very fast moving mobo)..I would be looking out for, and expecting to give way to ,traffic coming from starboard

 

[maxi77]

.......but, apart from information about a ship`s name, telephone number, and its bra size...What information does AIS give me that I`m not already getting with radar and MARPA? For those not familiar with MARPA its a facility with radar where you can track ANY object on the screen and you get SPEED, TRACK ,CPA,CTA.
What you get with AIS are ONLY THE OBJECTS WHO ARE TRANSMITTING THIS INFORMATION and NOT any of the objects that aren`t.
To my mind, there is a danger, not of not seeing the wood for the trees, but of not seeing the trees for the wood..and hence its a distraction .
Also, I never do anything wrong, so I don`t need any special monitoring or controlling...so ...is it worth paying out between 200 and 500 quid to have this AIS stuff onboard.

As you are clearly perfect I am surprised you can justifiy the radar with a full MARPA.

 

[idpnd]

and how long before somebody comes up with the bright idea ...for example..."only vessels transmitting AIS can cross a TSS"....and then somebody will decide, after looking at your track that you were not quite close enough (70, 80, 85, 89?) to the required 90 degrees

That's always been done by radar tracking anyhow

 

[NOHOH]

See You

As you are clearly perfect I am surprised you can justifiy the radar with a full MARPA.

Yeah.....but there`s no accounting for the imperfections of others eh? Pal

 

[Conachair]

To my mind, there is a danger, not of not seeing the wood for the trees, but of not seeing the trees for the wood..and hence its a distraction .

Following that logic the gps is a distraction as it stops you taking fixes and looking around

so ...is it worth paying out between 200 and 500 quid to have this AIS stuff onboard.

Yes as it draws bugg*r all power and works down to 10.5v. I know this for a fact soloing up the Brasilian coast when the batts failed. And you can see in about 2 seconds any cpas which should be watched.

 

[BrianH]

The example you give with the chart, however, is entirely unconvincing. Approaching a situation like that (even if I had a very fast moving mobo)..I would be looking out for, and expecting to give way to ,traffic coming from starboard

You missed the point entirely. The example merely demonstrated the principle; one can easily, with an open mind, see other cases where it could be advantageous to be aware of traffic behind islands, promontories, etc.

You originally asked, in a very revealing tone, what did AIS give that your radar didn't. You then went on to ignore, or rubbish, any input. Input such as low current draw, target ships' static data, including MMSI for DSC VHF calling.

Over the years there have been countless threads on these fora discussing AIS. There was always a hard core of dissenters, vociferously against the technology for some strange reason - some possibly because they couldn't afford it. That group has grown smaller and smaller as more people used it and saw its undoubted advantages. However, that group still exists and has seemed to have found a new flag-waver.

 

[NOHOH]

Are Barnacles just a pest that you scrape off?

.

You originally asked, in a very revealing tone, what did AIS give that your radar didn't. You then went on to ignore, or rubbish, any input. Input such as low current draw, target ships' static data, including MMSI for DSC VHF calling.

Over the years there have been countless threads on these fora discussing AIS. There was always a hard core of dissenters, vociferously against the technology for some strange reason - some possibly because they couldn't afford it. That group has grown smaller and smaller as more people used it and saw its undoubted advantages. However, that group still exists and has seemed to have found a new flag-waver.

I can`t imagine, what you THINK I might have revealed about myself....just as I can`t imagine what a reply from a Swiss/Italian HalbergRassy 94 owner reveals about himself when he replies in a manner that is dissmissive, sneery and insinuating and doesn`t answer my basic question...Namely... What else do you get from AIS apart from name, telephone number and bra size (ok that was meant to be a joke)...that you DON`T get from Radar/MARPA... (Apparently not very much, if anything...though I DO conceed that low power draw is an attractive attribute in even a useless box of kit) I can only IMAGINE that you have some vested interest in the manufacture or sale of this stuff.

If someone can convince me that this AIS stuff is really worth it, I might consider buying it.

There will now be a 5 minute silence on this thread whilst Barnac1e composes his apology for daring to presume that he knows anything about me.

 

[Joker]

... I can only IMAGINE that you have some vested interest in the manufacture or sale of this stuff ...

I think that deserves an apology.

 

[NOHOH]

Thats Rich

I think that deserves an apology.

Ha ha....thats rich coming from YOU ...(see earlier in this thread)

 

[Shorn100]

Unless things have changed, radar with MARPA used to require a gyro rather than a fluxgate to enable it to fix on to the target. Usually 50% of sweeps. Is that the case with yours? Gyros are relatively expensive.

2. Radar may not see smaller targets. A small fast boat can still do a lot of damage in a collision (even though they are meant to reduce speed in fog, many do not), possibly more than a ship.

So there are two things in addition to MMSI details where rdar is not as good as AIS. Having said that in an ideal world the combination of the two systems would be best.

On the plus side for radar, it can see those larger vessels which do not have AIS switched on.

 

[ColinR]

An awful lot of 'what ifs' in all this. What I know for a fact is that a simple AIS reciever is one of the best bits of safety kit to come along for a long time. Being able to monitor most large vessels from a considerable distance and call them up by name or MMSI if unsure of their intentions, being able to identify by name that ship that is on a constant bearing, get its actual course and speed and maybe give them a call, is a big bonus. Crossing the channel for example in poor vis, it makes a huge difference. Short handed or single handed I leave it on all the time with a guard zone. Of course it doesn't show small vessels and the odd ship has it switched off, but that doesn't negate its huge value.

Colin

 

[BrianH]

I can`t imagine, what you THINK I might have revealed about myself

Again, you miss the point, it was nothing about yourself. My "revealing tone" referred to an inferred scepticism of the technology, shared by many, which you have confirmed.

....just as I can`t imagine what a reply from a Swiss/Italian HalbergRassy 94 owner reveals about himself when he replies in a manner that is dissmissive, sneery and insinuating

Firstly, I fail to see what my location and boat have to do with the subject, other than some cheap implication about something or other that escapes me. And your interpretation of my attitude is paranoiac and insulting.

I can only IMAGINE that you have some vested interest in the manufacture or sale of this stuff.

This is preposterous bluster and even more insulting. Why on earth would I be using a cheap, seven year old Taiwan receive-only component that has not even been upgraded to modern standards such as the full addition of Class B protocols, if I had vested interests?

There will now be a 5 minute silence on this thread whilst Barnac1e composes his apology for daring to presume that he knows anything about me.

This is truly bizarre, words fail me - and they are not words of apology.

For the first time ever on these fora, I have found someone to put on my Ignore List <Plonk>.