AIS - am I missing the point ?

henryf

henryf

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Round the Island race today. An annual event and a stalwart in the Solent calendar. No problem with it whatsoever. But it highlights my thoughts on AIS. To me it should be treated like the fog lights on your car and only used sparingly.

To me - and I stand to be corrected, AIS is useful on a cross channel trip to identify course and speed of a vessel so I can plan how best to not collide. I could use my radar but AIS gives information straight from the horse’s mouth.

I could also identify the vessel and call up the bridge to discuss how best we pass each other so as to avoid any stress or confusion.

There is no point in my displaying AIS in the Solent, certainly not in good visibility. As can be seen from the screenshot using AIS in the Solent effectively renders it useless.

The AIS on our boat doesn’t have an on / off switch by default. Which seems odd. So I don’t have it connected yet.

I can see that AIS provides spy in the cab technology to authorities monitoring speed or restricted areas but the price of everyone operating AIS is shown below.

Am I missing the point or not fully understanding AIS ?

Every day is a school day.

Henry :)
 

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I use AIS having purchased it so my Dad could follow me on holiday. Trouble was he died before I fitted it!
I now use it so family can see where I am. When at anchor or moored up I turn it off.
The number of boats in marinas leaving AIS turned on when they aren't being used is something I don't understand.

Edit. I am 'following' a few boats doing the race today which you couldn't do years ago.
 
henryf said:
Round the Island race today. An annual event and a stalwart in the Solent calendar. No problem with it whatsoever. But it highlights my thoughts on AIS. To me it should be treated like the fog lights on your car and only used sparingly.

To me - and I stand to be corrected, AIS is useful on a cross channel trip to identify course and speed of a vessel so I can plan how best to not collide. I could use my radar but AIS gives information straight from the horse’s mouth.

I could also identify the vessel and call up the bridge to discuss how best we pass each other so as to avoid any stress or confusion.

There is no point in my displaying AIS in the Solent, certainly not in good visibility. As can be seen from the screenshot using AIS in the Solent effectively renders it useless.

The AIS on our boat doesn’t have an on / off switch by default. Which seems odd. So I don’t have it connected yet.

I can see that AIS provides spy in the cab technology to authorities monitoring speed or restricted areas but the price of everyone operating AIS is shown below.

Am I missing the point or not fully understanding AIS ?

Every day is a school day.

Henry :)
Click to expand...
Not that bad on the East Coast yet, but give it time. I also don't understand why people leave AIS on permanently, even when in the marina. We've even got some boats on the hard transmitting AIS !!

As for turning it off, you could have two options. You should have a "silent" option, which just stops you transmitting, and then you can have a power switch that stops receiving (and obviously transmitting too). It should also be possible to turn off the AIS overlay, so you could transmit but not clutter the screen with other vessels, not sure of the usefulness of that though.
 
The Round the Island Race is rather unique, lots of sailing boats rushing round a wee island at roughly the same time hence the busy screen. Each and every boat will have a small group of people who are following it with great interest. While you are looking at all of the boats they will be looking at one or several competitors boats.

surrounded.png

It does look like the Isle of Wight has been sucessfully surrounded (01/07/2023 1215 UTC)

The background for the development of AIS is interesting, think naval intelligence and tracking ships round the globe with dodgy cargos onboard and the CG being able to react early when a vessel stops and flags up not under command. There is an interesting YouTube video on the history of AIS, lots of interesting stuff about working out how to get an AIS transmission detected from a satellite if you are into geeky signal stuff.

As leisure sailors it is our choice to have it off, on or in stealth mode. The big ships don't have any choice, I've heard at least one Port Control radio a ship as they could not see them on their AIS screen.

Personally, I find the use of AIS really useful:
  • I can see what the big boys are doing (although sailing out of Plymouth have seen warships and Border Force vessels under way, but for obvious reasons not transmitting). Seeing One Manhattan bearing down on me one grey dawn while in a narrow channel in the Thames Estuary it was comforting to see that she had put in a 2° turn to port as the overtaking vessel about a nm earlier;

  • Should you call a Mayday the CG know where you are and where you have come from;

  • Friends and family can check where I am; and

  • The bar staff will know if I'll get back before last orders.
 
As a very early adopter even with radar I found it very useful and have watched its 'progress' with interest although I haven't been an active boat owner for 11 years now. The only vessels apart from the odd grey funnel line that I encountered not displaying or using were fishing boats and some very large ones at that. Even in the past there were always vessels that left it switched on when in the marina or alongside, at anchor it's probably marginal but could be useful to leave it on especially in a busy anchorage.
 
We use it in SCM as a means of tracking each other. I run the SCMCHAT forum and one of the features that I've built in to the Web site is an AIS plotter page for all the boats in our marina with AIS transponders. So, those who want, can be registered in our own SCM fleet. SCMCHAT only shows the SCM fleet boats. We also include the Brittany Ferries that we use to get to SCM.
I'm in Mallorca at the moment and JWs AIS has gone on the blink. I think rhe problem is antenna related but I haven't got the equipment on board to diagnose it until I get back to SCM.
 
AIS has limitations. When there are lots of targets, most devices start suppressing them, so not all boats transmitting are shown.

Also many fishing boats don't transmit on AIS.

In the Solent I turn the AIS alarm off - it goes off all the time. But it's still useful for identifying boats so they can be called up on VHF.

In poor visibility I use (and I mean actually use) radar as well as AIS.

Conclusion? Useful but neither essential nor a magic bullet.
 
AIS is a collision avoidance system and, as such, it is, to my mind, a massive contribution to safety. It is not intended, and is not reliable as, a vessel tracking system. Normally, it should not be left on when in harbour. However, a friend of ours who keeps his boat in France, uses it to check his boat is still there. On one occasion, he telephoned the marina to ask why they had moved his boat to an adjacent berth.

It must be a pain in the Solent but we have found it useful in France.
 
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FWIW, the Round the Island Race instructions do state that a tracker must be in use throughout the race so competitors don't have to much choice..

Screenshot_20230701-153207_Drive.jpg
 
franksingleton said:
AIS is a collision avoidance system and, as such, it is, to my mind, a massive contribution to safety. It is not intended, and is not reliable as, a vessel tracking system. Normally, it should not be left on when in harbour. However, a friend of ours who keeps his boat in France, uses it to check his boat is still there. On one occasion, he telephoned the marina to ask why they had moved his boat to an adjacent berth.

It must be a pain in the Solent but we have found it useful in France.
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I agree that it is intended to be a collision avoidance system but it was designed well and can be used for a lot more. Unlike the design of the DSC VHF system which is about as useful as a chocolate tea pot.
 
PaulRainbow said:
Not that bad on the East Coast yet, but give it time. I also don't understand why people leave AIS on permanently, even when in the marina. We've even got some boats on the hard transmitting AIS !!

As for turning it off, you could have two options. You should have a "silent" option, which just stops you transmitting, and then you can have a power switch that stops receiving (and obviously transmitting too). It should also be possible to turn off the AIS overlay, so you could transmit but not clutter the screen with other vessels, not sure of the usefulness of that though.
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I think you fitted mine on presto and I've lost the manual so I think it stays on all the time 😀
 
Talking to a First Officer the other day. He said if you have ais you exist if not you don't. He reckoned modern algorithmic radar was very good at filtering out yachts. He could have been talking nonsense of course.
 
PaulRainbow said:
I did indeed. A silent switch was not fitted (most people don't want one). There will be an on/off switch though. Feel free to PM or email me. Manuals available online: https://em-trak.com/wp-content/uploads/B900-Series-manual-EN-v2.pdf
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Thanks.

I have to say I don't think I would switch it off anyway. You did a great job, solar works a treat, heater works a treat and the AIS works perfectly.

Having it on crossing the channel gives a huge sense of securitythat these big boats can see you and you have a good idea of the closest point of approach. Coming back from Calais a couple of weeks ago I was talking to the coastgaurd about some rubber dinghy reports and then mentioned I was about to cross the shipping lanes, they replied that they knew as they could see me on AIS and were watching. Pretty re-assuring.

I can see that in the solent things can get a but cluttered that's an unusual atypical place. Actually it's not really a sailing place to be honest so best to discount.
 
Is AIS clutter an issue in any place other than in the Solent area?
I suspect not.

Where and when AIS is such a big clutter issue the simple solution is to switch the AIS off then the clutter disappears from the screen.

I do have a on/off switch but in a marina whats the issue with AIS transmissions ? Okay lots of potential for clutter but who cares really. Does anyone navigate in a marina using a chartplotter/mfd ?

On the River Trent and Humber we pass ships sometimes relatively close by. AIS is a great tool to help understand what the ships are doing.
 
Using Southampton Water frequently and not wishing to be 'ignored' by a Ferry I fitted AIS on my boat after reading this MAIB report

https://assets.publishing.service.g...e11d2af/2019_-_4_-_Red_Falcon_and_Phoenix.pdf

An AIS transceiver would have enabled the display of Phoenix as an AIS target on Red Falcon’s ECS, which was readily visible to the ferry’s chief officer, and the display of Red Falcon as an AIS target on board Phoenix.
 
I turn mine off when away from the boat. I set it to "harbour" mode in or near ports and anchorages to suppress alarms. I leave it on at anchor (on anchor watch).

Much of the time on passage I can't even see any other boats but it's nice to know someone else is out there. In the Solent I would probably leave it on 'harbour" as it would be permanently alarmed.

Verdict : really useful especially with commercial traffic and poor visibility.
 
Supertramp said:
I turn mine off when away from the boat. I set it to "harbour" mode in or near ports and anchorages to suppress alarms. I leave it on at anchor (on anchor watch).

Much of the time on passage I can't even see any other boats but it's nice to know someone else is out there. In the Solent I would probably leave it on 'harbour" as it would be permanently alarmed.

Verdict : really useful especially with commercial traffic and poor visibility.
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Not to sure what this "harbour" 'mode' is. I can set mine to silent or what some call stealth mode, and the alarm never sounds as I has set all the bits to 'off' as sailing in and near the Solent it would be going off all the time. It still highlights vessels on a converging course in red which is fine by me.
 
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