AIS in the Solent

jimi

jimi

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What a waste!!

Coming through the Solent on Sat morning, I went to check whether there was anything big moving so I could avoid. The screen was a mass of triangles causing so much clutter as to render it completely unusable.

Elsewhere it proved a very useful tool partic at night.


Can I suggest that leisure vessels are forced to turn off the transmitters within the confines of the Solent or any other areas where large vessels are moving in confined waters.
 
jimi said:
Coming through the Solent on Sat morning, I went to check whether there was anything big moving so I could avoid.
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I do that too, by looking outside the boat for very large pieces of steel moving up or down the channel. I find it works quite well, regardless of anyone else's triangles.

I genuinely cannot fathom the desire to look at an AIS display within the Solent. The CPA function doesn't work because the ships are manoeuvering, you know exactly where they're going to go because the big ones would need caterpillar tracks to go anywhere else, and on most systems the alarms would be blaring because you pass them (quite safely, outside the channel) a couple of hundred yards away instead of a mile. I don't even take the cover off my AIS display in the Solent in daytime.

(It can be helpful at night coming in from the east, but then all the nasty triangles are all tucked up in bed so I don't see them.)

jimi said:
Can I suggest that leisure vessels are forced to turn off the transmitters within the confines of the Solent or any other areas where large vessels are moving in confined waters.
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You can suggest all you like, but it ain't gonna happen :)

The correct answer is for the makers of the display software to pull their fingers out and add decent filtering capabilities. Handle the available information more intelligently, don't demand (ineffectually) that the amount of information be reduced.

Pete
 
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I wanted to be aware of any large ships movements, I was well aware that they were likely to change course but by spotting their presence early would give me advance warning. I too am a fan of MK1 eyeball at close quarters but find forward planning a distinct advantage when singlehanding on passage.

My point is that the vast quantity of AIS transmitters in such a small area renders their use totally counter-productive.
 
Twister_Ken said:
Some of us have been saying that for years. Haven't turned my AIS on yet this season, on either rx or tx.
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You might find that yours is transmitting anyway if it has power going to it because our Garmin one does if the NMEA 2000 cabling is powered up as it routinely is for the wind instruments, depthsounder and boatspeed to work. In order to prevent AIS transmission we have to use the separate AIS transmit 'off' switch, a separate switch installed between two of the tiny cables going into to the AIS transponder. It is still confusing because to prevent it transmitting you have to turn the AIS 'SILENT' switch to 'on'. Possibly others have yet to discover how it all works and are unaware they are transmitting 24/7. Turning the AIS to 'off' in our plotter menu merely stops the plotter/radar displaying other boat's AIS data, it does not turn off our own AIS transmitter, nor does turning off the plotter itself at it's 'power' button. :confused:
 
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Twister_Ken said:
Robin,

My AIS kit (from Digital Yacht) is wired (it's a user option) with a silent switch. It has it's own, switched, supply. When the unit is not switched on nothing happens, when powered with the silent switch off it's in RX mode. With the silent switch on, it is RX&TX. LEDs tell me what it's doing (or not).

http://www.digitalyachtamerica.com/...onders/product/32-ait2000-class-b-transponder
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Similar to mine then, but the 'SILENT' switch is a user option and has to beput in or not during installation, it is not on the unit itself nor is the switch even provided, there is just a brief paragraph in the instruction manual explaining how to install it. . I would guess a lot of folk are not aware that unless such a switch is fitted their AIS is a-pinging away regardless. our Garmin has LED lights too, but not much use if like ours it is mounted behind a panel out of sight.
 
jimi said:
What a waste!!

Coming through the Solent on Sat morning, I went to check whether there was anything big moving so I could avoid. The screen was a mass of triangles causing so much clutter as to render it completely unusable.
.
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Foggy, was it?
 
My B & G has the ability to turn off when you add the switch (which I am fitting as I speak)

As you say only a couple of lines in the manual, it's almost as if they do not want to advertise it!
 
jimi said:
No, it was a bright sunny day .. but perhaps the 357 leisure boats transmitting in the Solent thought otherwise.
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I think Bob's point was the same as mine - if it's a bright sunny day, why on earth are you peering at a little screen to locate the large ships which are perfectly visible to the naked eye?

Pete
 
DJE said:
Yes 12 is their working channel but they do hourly bulletins on upcoming movements on Ch14 IIRC.
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Ah, right. I've heard them announcing those (on 14, as you say) but I tend to just listen to 12 while I'm in Southampton Water or the central Solent. Fewer radio checks there :)

Pete
 
prv said:
I think Bob's point was the same as mine - if it's a bright sunny day, why on earth are you peering at a little screen to locate the large ships which are perfectly visible to the naked eye?

Pete
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+1. That's scary.
 
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