AIS

[claymore]

Is Webcrustaceous really the expert that he appears to be posing as, over on YBW. I realise that I have been in there when I said I wouldn't and for that I am truly sorry - but the question remains....

[Aja]

Claysie, just nipped over for a look-see.

I use http://www.shipais.com/showship.php?mmsi=235013197 a bit to see what is passing outside the front window
(that's the 'Jupiter' doing 12.2 knots by the way....).
I hope this doesn't make me sound like a geek.

Apart from a vaguely interesting discussion about VHF propagation these guys are really weird 'firing up their pc's and over-laying their gizmos". Some people use boating to get out and experience life, sadly not them. There is much more to life in my opinion.

Cheers

Donald

[Nick]

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They are having Colregs arguments based on AIS-predicted close approaches by ships over ten miles away.

I'm not an expert but I don't see the point. If you have your head stuck in a screen worrying about traffic over the horizon you could easily run into a much nearer non-AIS equipped vessel. Great in poor vis, but otherwise why not use the eyeball and only refer to the AIS if you are unable to take bearings or need the name of the vessel.

However, I have had a PM from Moody Nick accusing me of trolling so I would ignore anything I have to say on this subject if I were you.

[Nick]

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Claysie,

Your little snipe at me resulted in a full broadside from the obnoxious Jonjo aimed at Scottish sailors in general. I quote it and my reply below. Are you one of the sporran wetters to whom he refers?

Today, 18:14
You arrogant prat
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Originally Posted by jonjo
Excellent resource.

The live maps demonstrate so clearly why West Coast Scottish readers cannot comprehend the issues being debated. They would wet their sporrans navigating a yacht between Poole and Guernsey.

They don't have a clue and never will.

p.s. most of the AIS contacts on the Scottish west coast are shore stations.

You arrogant prat

I am interested in AIS not for dodging the Clansman in the Sound of Mull but for our next trip across the Bay and down the Portuguese coast in thick fog. I fully understand its value and its limitations, and indeed have been a staunch supporter of it and defender of its use in previous threads on here. I merely commented that you were misusing it if you were making course alterations at ten miles based on AIS data alone. As far as I can see I am not alone in that opinion.

Your assumption that because we are based up here we have not sailed elsewhere is patronising and typical of the conceited nonsense we have come to expect from you.

You take care now - I wouldn't want to hear that you have been run down in an AIS-assisted collision.

- W
__________________
Comprehensive UK sail cruising website
BlueMoment - blown away into the blue . . .

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Last edited by webcraft; Today at 18:21.

[Alcyone]

C'mon lads, you're better than this.

Just smile at em.

[puddock]

I like your style Nick....
I really do think you should be a little more diplomatic though.......... no, I don't really.

[sahona]

Now, if I wore a polisman's hat, Jonjo's name would be on the sheet of paper therein.

[puddock]

Classic retort.......

"I take it back - I am in fact rather looking forward to hearing about your AIS-assisted collision "

[Arghiro]

Don't let the bar stewards wind you up?

[ParaHandy]

.... a full broadside from the obnoxious prat Jonjo ...

Debating (eh?) with somebody who claims to be the first to show an interest in the thing "6 years ago" and which gives him an insight into the thing which lesser mortals will not have, is a waste of time ..?

There is a more worrisome aspect, which was alluded to by one individual and described in terms as being an advantage, and that's the ability of AIS to identify a ship and allow a yacht to call the ship up to ask what his intentions are. This seems to be quite common nowadays and is as likely to cause a collision as not. I heard one yacht being told to p*ss off in not so many words - he was in broad daylight and in the middle of the channel.

[claymore]

Webbingtons
You know I love you and being in love means never having to say sorry

[jim.r]

Well, I'm well impressed with AIS, however its just one of an armoury in our battle against the predatory steel!

[Nick]

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Well, I'm well impressed with AIS

So am I and I am on record as having said so many times. It is especially good for wee boats where there are weight, power and cost implications which preclude the fitting of radar. When I have said this I have regularly been shouted down by cretins who insist it is the tool of the devil. I have also said many times that if we take a trip South again fitting AIS is a prerequisite.

Now it seems I am arguing against another bunch of fools who seem to want to navigate by AIS at all times. They don't seem to understand that making a course alteration based on a CPA calculated by AIS from a ship twelve miles away is a mug's game. The CPA is based on data available at that time and predicted into the future. However, it is run by computer, not a crystal ball. There is no guarantee that the ship in question is not about to make a course alteration, and of course there is no guarantee that you in a saily boat will be able to maintain your course and speed - thus CPAs calculated from this sort of distance are at best approximations.

Of course, AIS can help delineate shipping lanes and you might be able on the odd occasion to make long-range decisions based on AIS data, but I would venture to suggest that these should be the exception, not the rule.

Para's observation about VHF-assisted collisions is very pertinent but the reverse is also true - if you really are uncertain in close quarters it can sometimes help, and as has been suggested in the Ouzo case could even have been a lifesaver. We once successfully called up a ship in poor vis / close quarters because we could read its name with binioculars. We asked if they could see us on radar, which they couldn't, but they said that now we had called them they could see us out of the window (big container ship, under half a mile). We asked if there were any ships behind them that we might have a close encounter with and they said three, one of which was about three miles back and indicating likely to pass very close. They gave us the name of the ship. A couple of minutes later at maybe a mile or a mile and a half we made out the other ship head on to us and called it up. We gave our position and said we intended to alter course to starboards, perhaps they would do the same. They appeared to be both surprised and pleased by our call, and we passed comfortably about half a mile or a bit less apart with no stretched nerves on either vessel.

Again, I have in the past been chastised for EVER calling up a ship by armchair sailors and radar warriors who think they know it all.

I think the point is, any skipper with a bit of experience and common sense will use all the tools in his armoury as he sees fit at the time. Sometimes it is useful to call up a ship by name, usually it is an unnecessary distraction and irritation to others and simple observation should be telling you what to do to stay safe. I would put the anti-collision tools in order of importance as eyeball/hand bearing compass, AIS and in occasional circumstances VHF - but above all a modicum of common sense and not the blind application of a 'one size fits all' rule or dictum one chants as a mantra on bulletin boards to make oneself feel important.

So - Para, Jimi, I agree with both of you - gies a kiss

Now, is there any advantage of a standalone AIS over a plotter overlay, and should we all get Class B transponders?

[jim.r]

Talking from my usual position of obdurate ignorance I like to postulate the following;

1) Ouzo, would not have helped .. it may even have lulled into a false sense of security cos our friend the Bilbao started turning. (Bears out you point of its historical rather than future data)

2) Calling up a ship on VHS may be possible in the wild wastes of Biscay where there's only one ship in sight, in the Channel with many more about its just a source of confusion.

[So_Sage_of_Lorne]

.

Now, is there any advantage of a standalone AIS over a plotter overlay, and should we all get Class B transponders?

Not that I can see other than reduced power consumption.
I find the AIS overlay is particularly useful on Radar.

Yes but with qualification.

One of the most annoying things about AIS transponders is the habit of large usually professionally skippered yachts leaving them switched on whilst tied up in a marina or harbour. If you are entering said marina or harbour you get a constant stream of dangerous targets. I would guess they would also be an irritant in more crowded waters though you can eliminate all but the closest three targets.