AIS

[JumbleDuck]

I don't want you to know where I am in my newly found secret anchorage with torquoise clear water, perfect holding, a dusky maiden singing lullabies on an old stone pier & haggises grazing quietly in the glen. You might come & anchor here too & start banging on about AIS versus radar or your new battery or something.

I presume that a torquoise is a blue-green turtle. I'll keep my eye open for them. Everything else you can get in Greenock, can't you, along with "stabbed" and "gonorrhoea"?

 

[Balbas]

With respect, I disagree. There are two ways in which any of these gadgets could have an adverse affect on safety: the absolute and the relative.

Absolute: someone who is so intent on playing with radar, or on spotting birds with a binocular, may consequently spend less time looking out and consequently hit something.

Relative: someone who spends a wad of cash on a radar may improve their safety a bit, but not as much as if they had spent the money on something else. An RYA theory course, for example, or a more reliable engine.

Of course many people will improve their safety, but it's not a given from loading the boat down with toys.

You missed 'Risk Homeostasis' from your list. Skippers keeping their perceived risk level static - so by adding more 'safety' (VHF, flares, liferaft, AIS, EPIRB, GPS, Chartplotter etc) simply means that they are prepared to add more risk to counter that which they perceive they have taken away.

From my point of view as someone buying their first yacht, I wanted AIS transceive, but cost was against me. I wanted TX so that a) the wife would be happy we were as visible as possible when we were on board and b) so that when I am solo sailing the wife knows where I am.

I settled for RX only because a) The cost was much easier to swallow and b) although not my usual cruising grounds I have sailed in the Solent when the chart is covered in AIS symbols so I simply turned it off.

 

[capnsensible]

The AIS versus radar thing has been discussed previously.

I don't have radar, I'm guessing in marinas about 60-70% of sailing boats have it although probably much much lower for boats my size (32 feet) and less ?

My personal reason for not having radar is that I don't think it's particularly useful. Firstly, the images are a bit like diagnostic medical ultrasound - rather tricky to interpret without experience - and I don't have the patience to buy it and learn how to use it in normal (good visibility) sailing conditions. Secondly, I'm not sure what it adds ? GPS gives my positional relationship to fixed stuff with much more accuracy. AIS gives my position relative to moving stuff more accurately.

The only situation where I can see radar being additionally useful is in fog when the other boat is not transmitting AIS - I hope rare and getting rarer as AIS becomes more and more the socially responsible thing to have.

Radar is clearly far superior because it shows things that dont have AIS. Which is a Lot Of Things. Just because some people cant be arsed to learn how to use it doesnt mean its not the best thing. Hence its constant use on Merchant Vessels.

At least your plotter will tell you where you are when you have to put out a correctly worded distress call when your tangled on a pot marker coz you were too busy looking at AIS to keep a proper lookout.

 

[Yealm]

Radar is clearly far superior because it shows things that dont have AIS. Which is a Lot Of Things. Just because some people cant be arsed to learn how to use it doesnt mean its not the best thing. Hence its constant use on Merchant Vessels.

At least your plotter will tell you where you are when you have to put out a correctly worded distress call when your tangled on a pot marker coz you were too busy looking at AIS to keep a proper lookout.

I guess we’ll have to disagree !

 

[Angele]

Leaving Cherbourg on Saturday to head home, we entered a dense fog bank even before we had left the outer harbour. I could see it ahead, so set the radar to transmit. The outer harbour wall, all buoyage and other vessels all showed up, overlaid on the chart on the plotter. A small French day (motor) boat was also heading out to sea about 50m on my beam. No radar (probably no AIS too). So, he had the sense of mind to change course and sit about 10m off my bum, as I escorted him safely through the outer harbour. Once out in open sea, I gave him a thumbs up and he headed off (to go fishing, I suspect) still blind in dense fog, but at least he know knew he wasn't going to hit the outer harbour wall. There had been a second boat ahead of me, picked up by radar but not visible. He appeared to be unable to find the exit. I could see from the radar that he had arrived near the eastern entrance but to left of the way out. Incorrectly he turned to port and continued parallel to the wall for about half a mile until he realised he had turned the wrong way and retraced his steps.

After an hour the fog cleared and visibility became excellent. Radar into Standby mode.

Only when I approached the shipping lanes did I turn on my iPad to display AIS (although my AIS transponder had been transmitting my position throughout). At one point, the target list showed over 200 vessels (or electronic AtoNs). In the first "lane" (note: not a TSS) I was the stand on vessel and not a single large ship of the dozen or more potential collision targets was showing as coming within a mile of me. All had turned a couple of degrees to port or starboard long before I saw them as a potential threat. In the second lane I was give way - motorsailing now. It was harder to see a way through that did not put me within a mile of at least one big ship. But, I saw a possible way through by passing close to the stern of one in order to stay clear ahead of the one behind it. So as not to spook him, with his ship name displayed on the AIS, I called him up on VHF to say that I was give way (he might have thought I was sailing) and that I intended to pass very close to his stern. He thanked me for taking the trouble to speak to him.

IMO, both AIS and radar are great. But they have different uses.

 

[GHA]

IMO, both AIS and radar are great. But they have different uses.

:encouragement: :encouragement: Exactly!

Close but different, you can't really compare them.

And hard to think of *any* argument against having a little receive box spitting out really handy information for little cost and little power, should you wish to turn it on and have a look

 

[Yealm]

Leaving Cherbourg on Saturday to head home, we entered a dense fog bank even before we had left the outer harbour. I could see it ahead, so set the radar to transmit. The outer harbour wall, all buoyage and other vessels all showed up, overlaid on the chart on the plotter. A small French day (motor) boat was also heading out to sea about 50m on my beam. No radar (probably no AIS too). So, he had the sense of mind to change course and sit about 10m off my bum, as I escorted him safely through the outer harbour. Once out in open sea, I gave him a thumbs up and he headed off (to go fishing, I suspect) still blind in dense fog, but at least he know knew he wasn't going to hit the outer harbour wall. There had been a second boat ahead of me, picked up by radar but not visible. He appeared to be unable to find the exit. I could see from the radar that he had arrived near the eastern entrance but to left of the way out. Incorrectly he turned to port and continued parallel to the wall for about half a mile until he realised he had turned the wrong way and retraced his steps.

After an hour the fog cleared and visibility became excellent. Radar into Standby mode.

Only when I approached the shipping lanes did I turn on my iPad to display AIS (although my AIS transponder had been transmitting my position throughout). At one point, the target list showed over 200 vessels (or electronic AtoNs). In the first "lane" (note: not a TSS) I was the stand on vessel and not a single large ship of the dozen or more potential collision targets was showing as coming within a mile of me. All had turned a couple of degrees to port or starboard long before I saw them as a potential threat. In the second lane I was give way - motorsailing now. It was harder to see a way through that did not put me within a mile of at least one big ship. But, I saw a possible way through by passing close to the stern of one in order to stay clear ahead of the one behind it. So as not to spook him, with his ship name displayed on the AIS, I called him up on VHF to say that I was give way (he might have thought I was sailing) and that I intended to pass very close to his stern. He thanked me for taking the trouble to speak to him.

IMO, both AIS and radar are great. But they have different uses.

Great post!

 

[capnsensible]

I guess we’ll have to disagree !

Yeah thats life. I teach people how to use Plotters, AIS, handbearing compasses, charts, radios and sextants, but I only know how to use radar proficiently, I leave teaching that to others.

But in experienced hands, its the puppys parts.

And tide tables and PILOT BOOKS, complte with yellow buoy solutions.

 

[Yealm]

Yeah thats life. I teach people how to use Plotters, AIS, handbearing compasses, charts, radios and sextants, but I only know how to use radar proficiently, I leave teaching that to others.

But in experienced hands, its the puppys parts.

And tide tables and PILOT BOOKS, complte with yellow buoy solutions.

Haha yes, absolutely !

 

[dom]

Oh dear, this is coherent, logical and safe - that much is beyond doubt.

But where's the passionate dislike of some inanimate little box of tricks? Where is the contempt for those who use it, and as for that ship, jeez!, applying the Colregs to the letter, clear indication of your intentions, a safe passing, and a friendly response. How dull is that?

You'll have only yourself to blame you know if you get us a good reputation with the big shipping co.s

Leaving Cherbourg on Saturday to head home, we entered a dense fog bank even before we had left the outer harbour. I could see it ahead, so set the radar to transmit. The outer harbour wall, all buoyage and other vessels all showed up, overlaid on the chart on the plotter. A small French day (motor) boat was also heading out to sea about 50m on my beam. No radar (probably no AIS too). So, he had the sense of mind to change course and sit about 10m off my bum, as I escorted him safely through the outer harbour. Once out in open sea, I gave him a thumbs up and he headed off (to go fishing, I suspect) still blind in dense fog, but at least he know knew he wasn't going to hit the outer harbour wall. There had been a second boat ahead of me, picked up by radar but not visible. He appeared to be unable to find the exit. I could see from the radar that he had arrived near the eastern entrance but to left of the way out. Incorrectly he turned to port and continued parallel to the wall for about half a mile until he realised he had turned the wrong way and retraced his steps.

After an hour the fog cleared and visibility became excellent. Radar into Standby mode.

Only when I approached the shipping lanes did I turn on my iPad to display AIS (although my AIS transponder had been transmitting my position throughout). At one point, the target list showed over 200 vessels (or electronic AtoNs). In the first "lane" (note: not a TSS) I was the stand on vessel and not a single large ship of the dozen or more potential collision targets was showing as coming within a mile of me. All had turned a couple of degrees to port or starboard long before I saw them as a potential threat. In the second lane I was give way - motorsailing now. It was harder to see a way through that did not put me within a mile of at least one big ship. But, I saw a possible way through by passing close to the stern of one in order to stay clear ahead of the one behind it. So as not to spook him, with his ship name displayed on the AIS, I called him up on VHF to say that I was give way (he might have thought I was sailing) and that I intended to pass very close to his stern. He thanked me for taking the trouble to speak to him.

IMO, both AIS and radar are great. But they have different uses.

 

[Angele]

You'll have only yourself to blame you know if you get us a good reputation with the big shipping co.s

Hmm! Good point.

 

[Triassic]

Leaving Cherbourg on Saturday to head home, we entered a dense fog bank even before we had left the outer harbour.......snip.......

After an hour the fog cleared and visibility became excellent. Radar into Standby mode.

Me, I would have just had another cup of tea and left when it was safe to do so. Joking aside this was a great tale and certainly illustrates the strengths of both radar and AIS, but it also lends weight to my argument that by having them sailers expose themselves to hazards they may otherwise have avoided. I know I've perhaps been a little tongue in cheek with some of my observations on this thread but sometimes things do need to be said. Why would you leave the sanctuary of a harbour in thick fog, especially when you know you intend to cross a busy shipping lane?

 

[Angele]

Why would you leave the sanctuary of a harbour in thick fog, especially when you know you intend to cross a busy shipping lane?

The fog wasn't actually visible from the marina, only having exited the inner harbour. But, in any event, I knew it was localised and would burn off within a couple of hours, long before I reached the shipping lanes. Also, if it had been good viz when leaving Cherbourg, that doesn't guarantee it would still be so when reaching the shipping lanes.

 

[dom]

Me, I would have just had another cup of tea and left when it was safe to do so. Joking aside this was a great tale and certainly illustrates the strengths of both radar and AIS, but it also lends weight to my argument that by having them sailers expose themselves to hazards they may otherwise have avoided. I know I've perhaps been a little tongue in cheek with some of my observations on this thread but sometimes things do need to be said. Why would you leave the sanctuary of a harbour in thick fog, especially when you know you intend to cross a busy shipping lane?

Good question, though those localised fogs do go with the area though. A couple of years ago I was in Alderney and decided to set sail for Guernsey in a real peasouper. My father and others questioned this decision, quick blast on the dinghy ashore, up the hill towards St Anne and just after the leading lights (c. 200m up the hill) the fog yielded to bright sunshine and one could see for miles around. Back to the boat, off we went, and sure enough the sun came out after a few mins.

It's not really possible to avoid these fog patches no matter how hard one tries and one can see evidence of this in the chunky radar reflectors most of the local boats are fitted with.

 

[Yealm]

Good question, though those localised fogs do go with the area though. A couple of years ago I was in Alderney and decided to set sail for Guernsey in a real peasouper. My father and others questioned this decision, quick blast on the dinghy ashore, up the hill towards St Anne and just after the leading lights (c. 200m up the hill) the fog yielded to bright sunshine and one could see for miles around. Back to the boat, off we went, and sure enough the sun came out after a few mins.

It's not really possible to avoid these fog patches no matter how hard one tries and one can see evidence of this in the chunky radar reflectors most of the local boats are fitted with.

Aaah - food for another discussion - the benefits of radar reflectors versus AIS !

 

[Praxinoscope]

In a way I can sympathise with dom’s observation ‘dull’. Isn’t part of the reason that the ‘majority’ (for Yealm’s sake I have put this as a caveat) of us sail and argue for minimum regulation of our sport is our love of freedom that we find when we have raised the sails and are using that bit of energy (the wind) that so far politicians have not quite found a way of taxing us and surely there is in most of us a bit of Capt Jack Sparrow?
Taking a boat out will never be safe, sure we can have all the gizmo’s under the Sun, but nothing is going to stop that one in a million chance when something drastic goes wrong, and at that point I would rather have been on watch looking out around me than staring at all the little screens.
My AIS alarm is set for 2miles, if it goes off I look around even harder to see if or what I’ve missed, still just have time to have a quick look at the screen if unsure, and take some form of evasive action.

 

[JumbleDuck]

You missed 'Risk Homeostasis' from your list. Skippers keeping their perceived risk level static - so by adding more 'safety' (VHF, flares, liferaft, AIS, EPIRB, GPS, Chartplotter etc) simply means that they are prepared to add more risk to counter that which they perceive they have taken away.

Good point, though perhaps that leave safety neutral rather than decreasing it?

From my point of view as someone buying their first yacht, I wanted AIS transceive, but cost was against me. I wanted TX so that a) the wife would be happy we were as visible as possible when we were on board and b) so that when I am solo sailing the wife knows where I am.

I have AIS mainly so that my other half can follow the crew and me as we meander our way around. It has never given me any useful information about an impending collision.

 

[Yealm]

In a way I can sympathise with dom’s observation ‘dull’. Isn’t part of the reason that the ‘majority’ (for Yealm’s sake I have put this as a caveat) of us sail and argue for minimum regulation of our sport is our love of freedom that we find when we have raised the sails and are using that bit of energy (the wind) that so far politicians have not quite found a way of taxing us and surely there is in most of us a bit of Capt Jack Sparrow?
Taking a boat out will never be safe, sure we can have all the gizmo’s under the Sun, but nothing is going to stop that one in a million chance when something drastic goes wrong, and at that point I would rather have been on watch looking out around me than staring at all the little screens.
My AIS alarm is set for 2miles, if it goes off I look around even harder to see if or what I’ve missed, still just have time to have a quick look at the screen if unsure, and take some form of evasive action.

Don’t quite understand the caveat bit ?!

 

[RichardS]

With respect, I disagree. There are two ways in which any of these gadgets could have an adverse affect on safety: the absolute and the relative.

Absolute: someone who is so intent on playing with radar, or on spotting birds with a binocular, may consequently spend less time looking out and consequently hit something.

Relative: someone who spends a wad of cash on a radar may improve their safety a bit, but not as much as if they had spent the money on something else. An RYA theory course, for example, or a more reliable engine.

Of course many people will improve their safety, but it's not a given from loading the boat down with toys.

Errrr ..... nope. A few logical errors in your post I'm afraid.

Firstly, I said "Each of these things produces an effect and there is simply no possibility that carrying any of these makes one less safe and therefore that effect must be to make one more safe, on average."

Whilst I accept that someone might invest in binoculars or AIS and then spend an inordinate amount of time fiddling about with it rather than using it properly for its intended purpose, the number of people who do this to such an extent that they actually reduce their overall level of safety in absolute terms to a level below that which applied prior to their purchase will be so small that, as I said, on average, the absolute level of safety must be increased rather than diminished.

Secondly, an increase in safety is an increase in safety if a person is safer after their purchase than they were before it. I'm not trying to debate whether a person might have increased their safety even more if they had invested in device A (engine / radar / whatever) rather than AIS, I'm simply addressing Triassic's the observation that "AIS may well make things easier for you, but don't be under the illusion it makes things safer."

It is impossible to conclude that, on average, an investment in AIS will not make things safer. :encouragement:

Richard

 

[Praxinoscope]

Hi Yealm
Re caveat
It’s just that I noticed you commenting on me putting a caveat in one of my previous posts, but since I wrote this, you seem to have deleted that particular post so just forget the caveat bit.