Sea me?

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chuzzlewit

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A year or so ago I seem to remember an article in PBO : an apparently well scientifically qualified writer was casting doubts. He suggested that Sea Me did not guarantee one would appear on a big ship's radar screen. Can anyone remember when the article appeared?
 
Actually no. I do remember that the assessment made of the new AIS transponders came up with the same result though. If the airwaves are busy due to dense traffic, then the low priority of a leisure AIS set will not allow itto poll so you won't be seen at all! Maybe that is what you remember?

Sea-me will respond to any X band radar that strikes it However, not all returns will be received by the radar. But the chance of achieving the requisite 50% for ARPA to aquire you as a target are greatly increased. The other downside is that ocean going vessels only reloy on their x-band sets when close to shore. It seems that nothing is perfect!
 
And even if everything goes as it should, there's no guarantee that some-one's actually watching the radar screen.

Relying on being seen is one thing, it's far better/prudent to keep a sharp look-out at all times. Eyeball MkI is often neglected.

Personally, I feel there's one lesson to be drawn from the Ouzo disaster: IT'S BEHIND YOU!!
 
Its just a 60dB amplifier sat between 2 wave guides. What comes in is amplified and squirted out much louder.

The normal reflection from the boat will still occur but an amplified and retransmitted signal will also return to the radar set scanning you. The emmission is omni-directional.
 
Sea Me definitely works on the X band nav radar. Therefore, very close to the coast, you are likely to gain a big increase in visibility in a merchies radar. When you are out in the middle of the channel, they are going to be concentrating more on their S band radar, and SeaMe does not work on S band.

Personally, I would rather know about them first, and make my own course adjustments first.

I like AIS Rx only - and very much like Shipplotter software.
 
For a while, I have thought that a composite of the Sea Me and the C.A.R.D. would be a useful device. The C.A.R.D. is an S and X band receiver with crude (4 quadrants) direction indication. If that was combined (or even a separate gizmo) with a Sea Me that works on S and X bands, it seems to me that a lot more bases would be covered.
Anyone handy with a soldering iron? Or know how to file a patent ...

Derek
 
Hi Mark!
I have been struggling with the idea of one of these Gismos myself but not sure of the value when in mid channel. I have conflicting advice from people who should know as to if the traffic in the mid-channel TSZ will be watching X-Band or not. What is your opinion?
If even 20% don't it seems a bit like shouting at a deaf crowd..... and paying rather a lot to do so.....
 
You will get conflicting advice on this. Personally from merchies I have been on, some do and some dont - problem for me is that you dont know who is and who isnt.

In any case, I prefer to know about them, before they know about me, so that I can manoeuvre into a position where I am not relying on them to alter. Thus I prefer to use AIS receive, plus a hand bearing compass/seaman's eye. I use software from www.shipplotter.com, cause its good, and provides an audible warning of vessels I consider to be a problem, and does a good CPA calculation. The trick then is to work out what ships that are visible, are not using AIS.
 
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If you have a SeaMe and a standard radar reflector (eg blipper) are there any implications?

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No reason why it should.
 
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