GPS system global failure

I don't have dozens of GPSes as some kind of obsessive backup strategy

Not sure I keep a gps unit in a tin.
Mind you, if lightening hit my boat the last worry would be wondering where I am.
Actually, that might be exactly what I would be wondering but I doubt a gps will help much at that stage ;)
 
Sailing in an area where our own MOD regularly carries out GPS jamming exercises, I don't think that having a spare one in a tin, would help very much.:D

Indeed - you will note in post 14 that in my opinion jamming or interference is by far the most likely form of GPS failure.

Pete
 
Sailing in an area where our own MOD regularly carries out GPS jamming exercises, I don't think that having a spare one in a tin, would help very much.:D

Have had that happen. We were near mid channel coming back from a fishing trip in not very pleasant for us conditions when along comes a warship. Well bang goes any indication from our electronics where we should go. We were heading due north so no real problem but it did have us searching for the reason our plotter had gone down. 20mins later all back to normal. I put it down to the power of their radar blotting all our kit out but it may have been a jamming thing.
 
Have had that happen. We were near mid channel coming back from a fishing trip in not very pleasant for us conditions when along comes a warship. Well bang goes any indication from our electronics where we should go. We were heading due north so no real problem but it did have us searching for the reason our plotter had gone down. 20mins later all back to normal. I put it down to the power of their radar blotting all our kit out but it may have been a jamming thing.

Almost certainly a very powerful radar; as I said in an earlier post referring back to experiences with GPS and radar in an aviation context, the device that had the hard-wired roof mounted aeriel (pointing skywards, rather than in all directions) was unaffected. The others were all nuked into submission until we flew somewhere else and, even then, needed a proper re-start.
 
When playing their various war games, Joint Warrior etc, the MOD deliberately jam GPS in large areas of the Minch and around Cape Wrath for days at a time. That wasn't the reason for the submarine HMS Astute trying to take a short-cut through the Isle of Skye.
 
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