Big ships turming off AIS

[Allowishish]

I'm sure this is nothing new but still something else to worry about.
http://www.google.com/url?sa=t&rct=...l/index.html&usg=AOvVaw3rknanjo7JvuRAXTOEQai4
that's why you keep a posted look out.

 

[Jackdaw]

There are both legitimate and nefarious reasons for turning off AIS, usually in bad parts of the world. Not really an issue where most of us play. But your other point is correct, you can't rely on AIS as a primary means of collision avoidance.

 

[jviss]

I'm happy to have AIS, and now even happier with a class B transponder. I've been in situations where I really wanted to be "seen:" leaving the L.I. Sound on a fair tide in total fog; leaving Newport in fog. Lots of ships.

 

[capta]

I guess we've absolutely nothing to worry about if some ship or boat turns off their AIS, since we don't have and don't intend to get AIS. Just don't see the value since we've got two radars, a few GPS units and a really, really good pair of stabilized binoculars.

 

[Ron20324]

...in situations where I really wanted to be "seen:" ..QUOTE]

Just turn it off at the dock, please.

 

[jviss]

Just turn it off at the dock, please.

Why? It will just show my location and that I'm going 0 kt. You'll know i"m likely on board, and you can easily make a DSC call to me if your radio is so equipped.

BTW, at the moment, it's "ON" if the navigation electronics breaker is on. So if I turn on the chart plotter, the AIS is on.

 

[jviss]

I guess we've absolutely nothing to worry about if some ship or boat turns off their AIS, since we don't have and don't intend to get AIS. Just don't see the value since we've got two radars, a few GPS units and a really, really good pair of stabilized binoculars.

There are benefits to an AIS receiver that aren't provided by the gear you have. For example, knowing a vessel's name makes hailing it infinitely easier, since you don't have to describe its position and hope someone realizes its them. Many won't answer hails unless you hail them by name. It also allows hailing by DSC, automatically, if your radio is so equipped. I think AIS is a tremendous value, i.e., functionality/cost.

Why two radars?

 

[Davidasailor26]

Why? It will just show my location and that I'm going 0 kt. You'll know i"m likely on board, and you can easily make a DSC call to me if your radio is so equipped.

True, but then when anyone with a receiver comes in to the marina their approach alarm will go off. And depending on the layout of the marina it might go off just when starting to turn into the slip - not a great time for buzzers and popping up window boxes.

 

[Bill Roosa]

For the Ham radio nerds, google AIS dongle. $25, software is free, runs on the computer, just have to buy the coax and antenna. OpenCPN will accept the computer output and put it on the map. No soldering (except the antenna) required

 

[capta]

There are benefits to an AIS receiver that aren't provided by the gear you have. For example, knowing a vessel's name makes hailing it infinitely easier, since you don't have to describe its position and hope someone realizes its them. Many won't answer hails unless you hail them by name. It also allows hailing by DSC, automatically, if your radio is so equipped. I think AIS is a tremendous value, i.e., functionality/cost.

Why two radars?

I have absolutely no interest in communicating with any ships, so I couldn't care what their name is. I avoid placing myself in harm's way by staying out of theirs when I am on a sailboat. When I was master of ships, I had exactly the same philosophy in reverse. Maybe if I was sailing the St Lawrence Seaway or the English Channel regularly I might be interested in AIS, but where I sail I can assure you the majority of the traffic I encounter doesn't have AIS, so it would be of little use to me. But quite honestly, the most congested waters I've ever sailed was the Red Sea (perhaps 150 ships a day or more) and were I sailing there today, I doubt I'd have AIS there either.
As for two radars, when I bought the boat it had a perfectly wonderful 48 mile Furuno radar at the chart table, of little use to me as a singlehander, so I added the Garmin unit to display radar on my 10" chartplotter at the helm.

 

[jviss]

True, but then when anyone with a receiver comes in to the marina their approach alarm will go off.

Ah, I see. Well, I'm not likely to be a problem in this regard, as I'm on a mooring. But operators are going to have to just shut off those alarms in harbors around here, as many are crowded with vessels docked with the AIS on.

Check these: Newport and New Bedford, this morning, i.e., not during the crowded summer months:

Screenshot 2017-12-09 09.17.46

• jviss
• Dec 9, 2017

Screenshot 2017-12-09 09.18.50

• jviss
• Dec 9, 2017

 

[capta]

Ah, I see. Well, I'm not likely to be a problem in this regard, as I'm on a mooring. But operators are going to have to just shut off those alarms in harbors around here, as many are crowded with vessels docked with the AIS on.

Wow, talk about way too much information! At first glance one could take all those docked AIS signals as vessels preparing to get under way, because why else would anyone want that unit functioning at the dock (or mooring), especially if no one was aboard? I see AIS as becoming the 'cry wolf' of modern navigation technology.
My second thought was that it was kinda creepy, like someone using a high powered telescope to peer in the windows of apartments around them.

 

[jviss]

I think it's great. You can see if the vessel is 'operating,' call it using DSC, etc. Also, for remote owners, as is the case for many of the vessels in these plots, you can see where your boat is, from anywhere in the world!

Many big yachts are chartered (Newport). Many (most?) fishing vessels are owned by folks who are not the operators (New Bedford).

It's nice to be able to see where your asset is.

There's no "cry wolf" situation here. The vessel really is there.

 

[SG]

We have an AIS Class B transceiver which shares our boats VHF. We find it very helpful because

• You share with the other boat the name and pertinent info: name, speed, dierection, CPA. When a commercial vessel wants to ask for clearance or give you a shout, they can easily communicate with you and each knows who, what, and where the other is.
• The range is multiples of the radars effective range. (At a closing speed with another vessel time isn't all that much in the shipping lanes we are in )
• You are a real target on the ships screen, not just a fuzzy something.
• In rough weather, heavy rain, or where intervening land, buildings or features blocks radar, you see "around the corner".
• While I am uncertain that it's always so, the USCG patrol boats and other security vessels seem less intensely or curiously interested in interceding our progress. The will occasionally hail us on the VHF.
• I have a close friend who is in Martinique now after making his annual passage from New England. He appreciates the general comfort instead of being "surprised" by a big container or other carrier coming to view out of no where.

Having said this, some fishing boats (not all that small) turn off their AIS because they don't want to reveal their posisition to the competition. I've been amazed how radar will not show a 70' steel trawler with out riggers and net gear deployed very well or consistently at a distance. (Yes, I do know how to tune my radar. ;^))). )

If power use, fuel consumption, etc. are an issue, it just gives you options or is another electrical burden.

I know sailors plyed the same waters that I'm in for hundreds of years without these benefits. I can't conceive of (say) sailing along Maine's coast or waters in fog, wind, currents, and rain without the panoply of redundant electronic "stuff"'that I rely on. I'm not as good as they were. ;^)))

 

[jviss]

We have an AIS Class B transceiver which shares our boats VHF.

I have everything networked together. I might upgrade the fixed VHF's because they are older and don't have many of the new, useful features, like AIS integration; 'though they are DSC radios.

I agree with your post, SG, well written and to the point. I'm sure people argued about having a marine wireless and RDF 100 years ago, and having a radar and Loran 70 years ago, GPS 20 years ago, and so on. These new technologies like AIS are good, and here to stay.

The only downside I can see with them is the cyber security risk. This is so for GPS, AIS, and even your boat's network with its connected autopilot, etc.

 

[Gunni]

Shared VHF antennae? How does that square with nav-critical use of the radio and AIS?

 

[SG]

Shared VHF antenna:

On a Class A unit it must be dedicated; however, a Class B sends out little bursts that are in perceptable. The receive function of the AIS isn’t functionally noticeable either.

You need a quality splitter, not all work as well. (For you, Gunni, I’d call Electronic Marine and ask Phil Mitchell if you’re interested).

The reason for the use of combination antenna for me was

• It puts the antenna as high as possible
• It meant not running another low loss cable
• It was, with the splitter nominally less expensive.

Functionally not any deficit, works as well, or better.

 

[Ron20324]

... I'm sure people argued about having a marine wireless and RDF 100 years ago, and having a radar and Loran 70 years ago, GPS 20 years ago, and so on. ....

The systems you mention are receive's. AIS sends your signal to many people who do not need to/want to see a non-moving boats- or worse yet boats sitting in their slips. It is those selfish boats that are causing problem for others. I compare this to truckers frustrations when passenger cars started getting CB, jammed the channels, and ruining what worked so well previously. The first skipper of maybe 100 in our sailing club bought AIS, and he was quick to advise others of all the boats sitting in slips- or on moorings- that he advised that until there was a way to shut off alarms triggered by these boat, say, within a half mile (or whatever). There were so many false alarms that it virtually made the system worthless unless out in the deep water channels. But, then, he could SEE those boats. And at the helm, he could not afford to be distracted to see if, indeed, anything was a REAL concern.

 

[SG]

On our chart plotters you can set the plotter to not display vessels that aren’t moving, Ron.

 

[bawlmer]

I have an AIS receiver and I sail in a congested area with many converging channels. The AIS gives you a good idea of what large commercial ships are out there and where they are heading. It is a good strategic tool to help you plan your route to the Bay. It can help you avoid any close quarters issues. That's all I use it for though.