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    Re: Researchers spoof GPS signals to alter superyacht'scourse
    From: Lu Abel
    Date: 2014 Apr 28, 15:04 -0700
    Alan:

    I don't think it's correct to characterize the Royal Majesty problem as "all the ship's navigational instrumentation 'not operating'"   The only failure was of the GPS system and that was due to the failure of an antenna cable.   The ship's navigational system did what any good navigator would do, it reverted to DR navigation.  But ....

    1.  Due to poor interface/display design, the failure of the GPS was not noted, so the ship's bridge thought it was getting accurate position information, and

    2.  There are strong currents around Nantucket Shoals.   Any good traditional navigator would keep a DR plot, but also note an Estimated Position, based on drift of the ship due to current, something the computerized system couldn't do, and lastly, a human problem:

    3.   Someone, for unknown reasons, had turned off the depth sounder.  There are shallows surprisingly far offshore from Nantucket and Cape Cod, but they are gentle shoaling, not sudden reefs.  There would have been plenty of warning from a properly operating and alarmed depth sounder.  

    Strangely, the ship's radar was in operation the whole time and targets were identified.   Actually MIS-identified.   If you look at the NTSB report, the ship's errant path led it a mile or two from a buoy.  Its correct path would have led it a mile or two from a different buoy.   Given the distance to the buoy and the fact that the buoy was to the west of the vessel and obscured by the glare of the setting sun, positive visual confirmation of the buoy's identity was not made.

    So I personally don't blame automation for the Royal Majesty grounding, but rather an over-reliance on a poorly designed system.   Thankfully, this problem resulted only in a soft grounding, not a loss of life.


    From: Alan S <NoReply_AlanS@fer3.com>
    To: luabel{at}ymail.com
    Sent: Monday, April 28, 2014 1:56 PM
    Subject: [NavList] Re: Researchers spoof GPS signals to alter superyacht'scourse


    Peter:
    Respecting all the ship's navigational instrumentation that was "disconnected"or not operating, seemingly without anyone noticing, I'm surprised that the ship's engine or engines were working. It's not my intention to play the role of "smart-ass" however the degree to which necessary attention was lacking strikes me as amazing.
    Alan

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