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    Re: GPS jamming concerns
    From: Mark Coady
    Date: 2016 Aug 9, 10:26 -0700

    “GPS blindness”

    Speaking strictly from a marine vessel operation perspective; the overall picture being discussed indicates that for most of us in non-war zone areas, large areas of GPS blackout from hostile activity are for the moment very low probability events at sea. 

    That said, I observe that in the precision electronics age of navigation, even respected professional sailors and navigators, fall prey to what I call “GPS blindness”.

    Like “highway hypnosis”, whereby you hypnotize yourself with the dotted line till you fall asleep and crash, “GPS blindness” is a result of lulled complacency, with its troublesome little demon called distraction then whispering in your ear.   

    Simply put, super easy single source position input lulls us and renders us easily distracted to the point where we stop actively looking for danger. From my conversations with a fair number of shipwrecked sailors, this seems to be the ultimate cause of many vessel groundings and accidents (and don’t get me started on “asses with autopilots”).  It isn’t the GPS that’s the problem, its human frailty.

    “Colregs” too has repeated admonitions to use “all available means” to be on constant alert for danger of collision.

    When I navigate, I discipline myself to do a constant cross check of data (I consciously challenge myself).  Is my compass heading correct? Do the steering compass and GPS compass headings make sense, compared? Does the radar make sense with the GPS? Does the electronic chart make sense with the electronic ones? Does the sounder contour seem to follow charted depths? Do my pre-plotted courses match up with all my input data? even.....are the wind and waves making sense? etc....etc...

    This follows the one most important rule of navigation:  “never depend on a single source of information” regarding your position. I constantly demand a cross check and stop and figure out what’s wrong when an input doesn’t add.  So far so good, the discipline has worked and I am undamaged in many years on the water. I have found some good ones over the years too...including absent mindedly putting the dive expedition 200 lb pull retrieval magnet in the closet down below....and too close to the steering compass.

    Blind faith in a 99.9xxx (very reliable) source seems harmless, but it unconsciously can lead to dangerous behaviors.

    So this takes care of piloting waters, what of far from land?

    With celestial, I see a great way for the open water GPS dependent person to have an alternate input to sustain that alertness, if nothing else.  Yes I know the best backup to a GPS is another waterproof GPS, but I personally want an independent second input, an alternate thinking process, a sun or star bearing to check my compass. I want that second fix, to see if something has gone amuck or I got stupidly complacent.

     If I do celestial alone, I would use sights to check sights, common sense rules for quick reality checks on my decisions.  Good plots to see if I calculated the absurd, like my old duffer did 20 knots today....

    So I for one want a backup to GPS, I don’t care if it’s because the bad guys learn to jam or spoof the world, shoot down satellites, or old Mr. Sun vomits out a gigantic solar blob and kills all reception. I want it anyway to keep me awake, to keep me on my toes, to keep my awareness and thinking sharp.  That alone is reason enough without considering pending doomsday events.

    I used to have a picture in my pilothouse from the internet.  It was a shipwreck sticking up out of the water.  It is captioned: “The purpose of your life could be to serve as a warning to others”.  I had it as a reminder for constant alertness for both the lunatics around me..  and my own frailty to distraction and complacency.  Those to me are the greatest real enemies in modern navigation.




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