Since this is a relatively new technology I thought some here might be interested in screenshots of AIS traffic in the central English Channel taken while sailing cross channel.
This one made a night Channel crossing more interesting. I nudged the swmbo awake at 3 am and asked her if she wanted to see the QE II cross 1.5 miles behind but she feigned disinterest and went back to sleep. In my defence I must add her watch should have started 1 hour earlier!
We have just fitted the new Raymarine AIS250 unit and used it this weekend going cross-channel. We called up one ship asking them for their intentions. They then proceeded to divert behind us. ;-) Well we were racing!
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That is a terrific AIS reception view, seems to be 100 miles across. What is the elevation of your aerial?
My pushpit mounted aerial picks up most stuff at 6 miles, so my screenshots do not paint a full picture of traffic in the 6 to 12 mile range. I have noticed a blind spot which coincides with the mast, targets forward and slightly to port do not show up until 3 miles.
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And this is a ShipPlotter view
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That is a terrific AIS reception view, seems to be 100 miles across. What is the elevation of your aerial?
My pushpit mounted aerial picks up most stuff at 6 miles, so my screenshots do not paint a full picture of traffic in the 6 to 12 mile range. I have noticed a blind spot which coincides with the mast, targets forward and slightly to port do not show up until 3 miles.
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From home, antenna height about 15m above sea level and the Purbeck Hills mostly in the way. It was a good VHF propagation "ducting" day. My range is normally about 27nm and best has been 147nm.
The best I have had so far onboard is about 25nm with a masthead antenna but will get a better idea soon when we go X-Channel.
ShipPlotter is used as the AIS decoder from a comms receiver FM discriminator output in both installations, I don't have a dedicated AIS receiver.
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But you have no chart!
This is from Seaclear.
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For collision avoidance I find the simple radar like projection of Yacht AIS is perfect for the job. The program is overpriced for what it does but I doubt I will shift to something else until the trad plotter programs provide an AIS-only declultter mode.
A full 15" screen chart at the nav table would be nice but in the prep time with the new laptop I did not know how to go about setting up a small scale mid channel electronic chart for SeaClear.
Guess I should make full use of the PC and run both programs off a serial port relay software gadget.
Example from Seapro, south of Wight, ferries going north-south, us trying to go north-east, traffic east-west and west-east. If I remember there were 11 targets.
Maptech Chart Navigator Pro with NASA AIS engine and a masthead mounted VHF antenna through a JG Tech splitter. Range is around 13-14 NM max with our masthead about 17m high.
As you say, the Napoli. Not sure whether it's 'The' Napoli. This was 4th August 2006 and the Napoli in the screen shot was coming down the Irish coast. The shot below (day colours now) shows some of the info you can get from AIS (this is another target - obviously). If you scroll down you can see the tonnage, destination etc. I don't have a screen shot of the info on the Napoli to see if the size fits. Does highlight though how having an AIS transmitter on your ship/yacht means that you'll never know who's watching you!