Garmin chartplotters: not show AIS ATONS

[Copinsay]

Hello All

After a great deal of tenacity and the usual excellent after sales service from Chandlery, Sailing Clothing & Boat Electronics | Gael Force Marine I wanted to flag up what turns out to be a limitation seemingly on all Garmin chartplotters, in that they will not show AIS equipped Aids to Navigation, such as buoys, lighthouses, etc.

For some time I’d been sailing right up to the increasing number of such ATONs here in Orkney and West Coast Scotland without them showing on screen as AIS targets - all other AIS equipped ships showed up fine. My Marinetraffic.com base station has no such problem getting the signals either, so it was clearly a problem on the RIB setup.

After Garmin online technical support twice (and falsely) blamed my AIS transceiver (Advansea TR-200) for the error, the welcome intervention by Alex Collard, Garmin Marine Support Specialist, has led to the official statement that (and I quote from the latter):

"As promised I have looked into the AIS issue you had reported and I have spent a lot of time this morning discussing this with our software/engineering team.

Currently, no Garmin plotter will show any type of symbol information for message 21 which is the message that is sent out by these buoys.

I have been told that this is something we are looking into for the future, but currently this is not something our equipment will support. Please accept my apologies for the time it has taken to provide you with the information required, however please let me know if you have any additional questions."

I'd been trying to get to the bottom of this for some time, with initial - and wrong - responses from Garmin including:

"Our range of plotters are full compatible with ATON (Nav Aid) targets."

"The device, if up to date should be able to display these."

So I've also suggested to Garmin that rather than making assertions that something will work (when it actually won't), and causing needless and abortive hassle for customers, they should check their facts first :o)

To his credit Alex Collard has done a great job in clarifying that there is a problem, but sadly there's no apparent timescales for when this will be put right. Which is a real shame as seeing AIS equipped ATONs is I suggest a pretty important bit of functionality these days.

I hope this helps anyone else who may be needlessly struggling with this.

I also hope this publicity puts some pressure on Garmin to do a software / firmware update to correct this. If the later is something you'd like addressing too, I suggest you email Alex at Alex.Collard@garmin.com so he can let his colleagues know of the demand for this putting right.

Any other comments welcome - especially if by some miracle you have AIS ATONs showing on a Garmin chartplotters.

Also do folks know of which other makes / models of chartplotters do show AIS ATONs when connected to an AIS receiver / transceiver?

Best wishes

Steve

[gotchiguy]

This is a very interesting post and I am looking forward to people's response to it, and hopefully subsequent action by Garmin.

I have also noticed this phenomenon before as there are one or two navigational marks which appear to give out an AIS signal in our area on marinetraffic, but not on the plotter when approached (Garmin 7012 and Raymarine E80, Digital Yacht AIT1000,AIT2000). I had always made the assumption that these stations were infact Class E AIS stations, and that there was no local transmitter at the site.

Some quick research would suggest that this may be the case, especially for shore based sites such as coastguard buildings, but that also "synthetic ATONs" exist whereby the position of the AIS target is actually transmitted from another location, it would be interesting to know if this is the case with those around Shetland or if there are indeed transmitters fitted to the buoys and marks themselves.

I am quite surprised that Garmin specifically has this issue, as they have been the first of the majr manufacturers to really get to grips with AIS integration, and in an update a couple of years ago they were the first to really manage AIS SART transmissions and even SART test tranmissions.

Panbo: The Marine Electronics Hub: AIS MoB & SART display, Garmin nails it?

[Copinsay]

Thanks for this - glad to know I'm not on my own.

To answer one of the points, these are buoys with the AIS transmitters on them, rather than synthetic ones. That thought did occur to me as it could explain why they were not seen when you were right up to the physical mark, if eg, there was low signal strength from the base station.

For example, this is one (Orkney not Shetland) I went right up to, to test that it wasn't poor signal reception:

"AIS is being transmitted as an Aid to Navigation (AtoN) from this buoy station"


Northern Lighthouse Board - Scotland Orkney Islands Scapa Flow

Also Advansea (my AIS transponder maker) have done all the tests to check the ATON AIS data is being put out on the NMEA data string.. And now that - to their credit - Garmin themselves have admitted the problem, I'm convinced that's where the problem lies.

As you say, seems quite poor that Garmin have not addressed what is actually a really important application of AIS.

Please do email Alex.Collard@garmin.com at Garmin if you haven't already done so and encourage others to do the same, do get a fix prioritised.

Best wishes

Steve

[gotchiguy]

I happened to connect my AIT2000 to the laptop today, and in the list of other vessels it had two or three ATONs. So I can confirm that my Garmin doesn't show them at all.

For some reason the AIS has suddenly quadrupled its receiving range, it is now picking up vessels over 90nm away whilst inside a metal hanger... I don't understand! Having checked the vessels listed with marinetraffic it is definitely receiving them. The only thing I can think of is that these signals are being repeated from somewhere? I took these pictures the other day on the water, I just couldn't believe it was seeing these vessels so far away. If definitely didn't used to have such an impressive range. What do you usually get?

[Copinsay]

Hello All

Just for those interested to see how it's done, here's one of our local buoys that highlighted the issue for me, showing the recently added AIS transmitter added on the top, as an integral part of the lantern... Tidy job.

You can see it on Marine Traffic here:

FLOTTA GRINDS BUOY - Port Hand Mark: current position and details | MMSI 992351083, Callsign | Registered in United Kingdom - AIS Marine Traffic

Cheers

Steve

[Copinsay]

Originally Posted by gotchiguy

For some reason the AIS has suddenly quadrupled its receiving range, it is now picking up vessels over 90nm away whilst inside a metal hanger... I don't understand!

One reason could be that atmospheric conditions can temporarily "bend" VHF radio signals around the earth, known as a "lift", so the range is a lot farther than you'd expect. Can often happen when there's high pressure.

VHF/UHF Propagation - Radio Society of Great Britain - Main Site : Radio Society of Great Britain – Main Site

For example, you can see the average range of my AIS base station here:

Details for AIS station Mull Head Deerness - AIS Marine Traffic

...but when there' a lift on it will extend across to Norway. Range from here is a lot better anyway as the base station is at 50m asl, but you still get the effect.

At times I can hear Norwegian CG stations on CH16 too, but only a few times a year.

Are you still getting that great range or has it settled down now?

Steve

[Pikey Dave]

Originally Posted by Copinsay

One reason could be that atmospheric conditions can temporarily "bend" VHF radio signals around the earth, known as a "lift", so the range is a lot farther than you'd expect. Can often happen when there's high pressure.

VHF/UHF Propagation - Radio Society of Great Britain - Main Site : Radio Society of Great Britain – Main Site

For example, you can see the average range of my AIS base station here:

Details for AIS station Mull Head Deerness - AIS Marine Traffic

...but when there' a lift on it will extend across to Norway. Range from here is a lot better anyway as the base station is at 50m asl, but you still get the effect.

At times I can hear Norwegian CG stations on CH16 too, but only a few times a year.

Are you still getting that great range or has it settled down now?

Steve

A few years ago, we were diving in Normandy & had cause to call the coast guard for a minor incident. The call was answered clear as day by Solent coastguard who went on to manage the whole call & liaise with Cherbourg coasties.