AIS toggle between sail/power?

[arcbennett]

I have a passive AIS receiver on board by 39ft cutter, and am thinking of upgrading to one that transmits my position and details. On my receiver's tote, I note that transmitting AIS usually declare whether the vessel is under sail or power. So far, so good.

Searching the market, I can find no active AIS that offers what I'd call a switch for the user to easily (Force 6, in the dark) switch the boat's setting between power and sail.

Does anyone know of one that provides such a facility? Enquiries at the Southampton Boat Show tended to raise bemused bafflement amongst the sales people, indicating they thought it unimportant. But as the 'when in sight' colregs are entirely different depending on the mode of one's vesseI's propulsion, I'd say it's extremely important. After all, we change our navigation light settings as we alter between power and sail. We should do the same if transmitting our AIS signal.

Or am I missing something?

 

[Momac]

I think AIS does not have the facility to transmit this and it it did I don't suppose anyone would notice.

 

[{151760}]

Quick research tells me that the item transmitted by AIS that tells others whether you're under sail or engine is Navigational Status. The parameter within this section that defines motoring or sailing, or 'not under command' etc. is supposed to be entered by the crew. I suppose there's an item on a menu somewhere that needs to be changed.

 

[GHA]

I think AIS does not have the facility to transmit this and it it did I don't suppose anyone would notice.

It's code 36 for sailing in vessel types. Probably would be useful if and when anyone used it, it's certainly handy when you see a survey vessel or tow etc showing up on ais.

https://help.marinetraffic.com/hc/e...-the-significance-of-the-AIS-SHIPTYPE-number-

Edit - Nope, wrong! Stormnorm is right, navigational status. Does class B broadcast that?

 

[Sandyman]

Could you explain a bit more about why you would want to do this ? Im not getting it & can't see why you would want to be able to do it..

 

[johnalison]

Could you explain a bit more about why you would want to do this ? Im not getting it & can't see why you would want to be able to do it..

A digital motoring cone?

 

[john_morris_uk]

I haven't seen the option in any Class B AIS I've used and I don't think it's necessary.

The relevant and applicable rules are 'for vessels in sight of each other'. The AIS gives you extra information but is only an aid. Once you're visible from another vessel, they should either see sails/no sails/sails with a cone by day, or the relevant lights by night. Hence there should be no confusion.

The ONLY time I've called a ship (recently) was to tell a ship that we were motoring and he couldn't see my cone as it was obscured. It changed our status from stand on to give way and I said I would alter to starboard to increase our CPA from the 300 metres it was showing. He grunted an appreciative response as he was about to alter for what he thought was a sailing vessel. In normal situations it should all be clear. I think professional watchkeepers are quite capable of noting that our AIS tells them, "Sailing Vessel" and then looking through their binoculars to see if we are actually sailing.

 

[PaulRainbow]

Class B AIS transmits (amongst other things) "Vessel Type" and "Nav Status". So you might be a "sailing vessel" (fixed parameter programmed into the AIS) and you might be "underway". Whether or not you are sailing or motoring, you will still be a sailing vessel underway.

 

[macd]

I think AIS does not have the facility to transmit this and it it did I don't suppose anyone would notice.

It does, but the 'A' in 'AIS' isn't actually very automatic. This is especially the case with yachts parked in marinas.
I wouldn't worry, arcbennet: as others say, it's up to the watchkeeper to work it out by other means.

 

[GHA]

Class B AIS transmits (amongst other things) "Vessel Type" and "Nav Status". So you might be a "sailing vessel" (fixed parameter programmed into the AIS) and you might be "underway". Whether or not you are sailing or motoring, you will still be a sailing vessel underway.

Which message type is class B nav status in? Not in 18..

[h=3]Type 18: Standard Class B CS Position Report[/h]A less detailed report than types 1-3 for vessels using Class B transmitters. Omits navigational status and rate of turn

 

[ShinyShoe]

So for clarity:

Nav Status is the message that will do what you want. Nav Status 0 = underway on engine, 8 = underway on sails.

BUT Nav Status is Class A only.

Would kind of make sense to have a switch or 'sensor' from engine or something that toggled that. Mind you it'd make sense to automate the engine being on to do Nav Lights and I'm guessing most people don't! However with AIS you would also need to know you were at anchor, aground, NUC etc which means you'd be better having an easy way to set that on the AIS or plotter... ...or just use Class B and the big ship will use Mark1 EyeBall to decide what to do

 

[ghostlymoron]

Not so easy at night.

I haven't seen the option in any Class B AIS I've used and I don't think it's necessary.

The relevant and applicable rules are 'for vessels in sight of each other'. The AIS gives you extra information but is only an aid. Once you're visible from another vessel, they should either see sails/no sails/sails with a cone by day, or the relevant lights by night. Hence there should be no confusion.

The ONLY time I've called a ship (recently) was to tell a ship that we were motoring and he couldn't see my cone as it was obscured. It changed our status from stand on to give way and I said I would alter to starboard to increase our CPA from the 300 metres it was showing. He grunted an appreciative response as he was about to alter for what he thought was a sailing vessel. In normal situations it should all be clear. I think professional watchkeepers are quite capable of noting that our AIS tells them, "Sailing Vessel" and then looking through their binoculars to see if we are actually sailing.

 

[{151760}]

I have an AIS reading app on my iPad. All of the leisure vessels in the Solent at the moment with AIS show Navigation Status. A few show it as under sail, most as under engine. Some of those showing as under engine are definitely sailing, but others I can't verify. A very few show 'not defined'. Surely most of these will be class 'B' equipment? Some are sailing schools, but most are private.

 

[ShinyShoe]

So is that App showing you AIS retrieved from the Web?

If its class B kit it can NOT send a Nav Status message, and the VAST majority of the Pleasure Vessels transmitting AIS in the Solent today are class B's. If we could have an MMSI for a couple of pleasure vessels apparently transmitting their Nav Status that might be useful...

 

[Bru]

Some, perhaps a good number, of those leisure vessels will be using an app such as Boatbeacon etc rather than, or as well as, a class B transceiver

The apps have a field for vessel status which if set is displays on the various vessel tracking websites. That info is not, however, displayed on AIS receivers (whether class A or B)

The app data is also persistent. It remains in the tracking sites databases until it's updated even if the app is stopped (data such as vessel status, destination and ETA etc can therefore be weeks, months or even years out of date! This is not important since this data only exists in the online databases, it is not visible to other vessels using AIS equipment on board)

 

[{151760}]

So is that App showing you AIS retrieved from the Web?

If its class B kit it can NOT send a Nav Status message, and the VAST majority of the Pleasure Vessels transmitting AIS in the Solent today are class B's. If we could have an MMSI for a couple of pleasure vessels apparently transmitting their Nav Status that might be useful...

Yes, it's a web-based App. Try these; sailing at just before 13:00 235078767 and 235050524.
You're quite right that only Class A transmitters use the Navigation Status. The manual for the Icom MA 500-TR shows quite clearly that the menu item for Navigation Status is not used on Class B equipment. I assume that my app has 'under way using engine' as a default. So as to the OPs original question, it seems that Class B AIS equipment does not have the facility to change that particular parameter.
I have to say that I'm also of the opinion that it's of little use. I can conceive of situations in very poor visibility where it might be useful to know what the approaching vessel's method of propulsion is, but it's certainly not crucial.

 

[ShinyShoe]

Yes, it's a web-based App. Try these; sailing at just before 13:00 235078767 and 235050524.

235078767 is an 11m sailing vessel called Faux Pas, it is transmitting rather than / or maybe as well as sending via a phone ap, as the data has come via John-Ambler.com's receiver in Cowes. It is transmitting a status of Underway, but not its means of propulsion...

235050524 is a 10m sailing vessel, being received by Selsey Bill. It also left Cowes, but Marine Traffic says it was headed to Portsmouth, Class B kit can't specify a destination, so either they are supplementing from an Ap or Marine Traffic infers that as they arrived in P'mouth.

I wonder if your we ap is inferring that because these are sailing vessels they are underway by sail if they are underway.

Be interesting to see what it says for 235090959 which has no sails... I suspect if the vessel type is 'sailing' its populating underway as sailing, and if its pleasure craft etc then it populates underway with by engine...

I have to say that I'm also of the opinion that it's of little use. I can conceive of situations in very poor visibility where it might be useful to know what the approaching vessel's method of propulsion is, but it's certainly not crucial.

And unless it was 100% reliable it becomes a problem anyway...

 

[prv]

Not so easy at night.

Huh?

Far easier at night, because your lights clearly show whether you're under power or sail. The majority of yachtsmen don't bother to hoist a motoring cone, but most will select the correct lights (excepting the occasional idiots anchored with tricolour and bow lights on...)

Pete

 

[prv]

So for clarity:

Nav Status is the message that will do what you want. Nav Status 0 = underway on engine, 8 = underway on sails.

BUT Nav Status is Class A only.

Exactly. The subject has come up before, which led me to check the IMO specifications and find that Class B AIS simply doesn't have the relevant message and so fundamentally cannot transmit whether a vessel is under power or sail. This seems a great pity, as it's Class B users who are far more likely to be aground, under sail, fishing, etc, but there's nothing that can be done about it without redefining the AIS protocols and waiting for all the installed equipment to catch up, a process that would take decades if it ever happens at all.

Anything else in this thread is a red herring.

Pete

 

[PaulRainbow]

Hadn't noticed nav status was class A only, so i'll stand corrected there.

I think it'd be a waste of time anyway, about as reliable as a motoring cone. I regularly see tugs and pilot boats on AIS with nav status "at anchor", but clearly underway.