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    Re: News Item on Over-reliance on GPS
    From: Lu Abel
    Date: 2008 Nov 03, 21:48 -0800

    I don't know about carriage rules, but what you suggest would make a
    heck of a lot of sense.
    Many EPRIBs now have built in GPS's.
    Many DSC (Digital Selective Calling) VHF radios have a data connection
    to a separate GPS so that when the big red Mayday button is pushed the
    vessel's Lat and Long is included with the digital distress message.
    I've heard this capability described as "taking the 'search' out of
    'search and rescue'"  In fact, some but not all DSC radios and GPS sets
    on a receiving vessel can actually take the GPS position of a Mayday and
    do the equivalent of pushing the Man Overboard button on the GPS set,
    instantly giving the distance and bearing to the Mayday call.   While
    I've never personally experienced it, I can imagine that it would allow
    me to very quickly decide if I could help in the situation and how to
    get there most quickly.
    A friend of mine just purchased a handheld VHF (US law does not require
    handhelds to have DSC capability) with DSC and a built-in GPS set.
    Unfortunately, the functionality of the GPS is very limited (lat/long
    display and that's about it), but I could see that particular radio
    being part of an emergency kit and providing one with both a GPS and a
    hand-held radio, which are probably two of the most important pieces of
    gear to have for summoning help.
    By the way, in learning about the USS San Francisco for today's earlier
    discussion, I found a Wikipedia page on post 2000 sub "incidents":
    I hadn't heard of the grounding of the USS Hartford.   Right on target
    for our discussion.  Sub had just left dock in Sardinia (so she's on the
    surface) and started on a multi-turn path to exit the harbor when her
    electronic navigation system crashed.   Navigator and assistants were
    desperately trying to reboot the thing (I can just see the Microsoft
    boot screen now :-) ), captain continued on course but with no bearings
    and poor DR and in fact increased speed, waypoints are entered into some
    GPS system (a backup?) incorrectly which in turn causes the sub to turn
    too soon.  Someone on the navigation team notices the fathometer
    dropping and repeatedly gives the alarm (which is ignored in the
    confusion).  The tug escorting the Hartford notices she's heading for
    the shallows and tries to contact her on both VHF and a cell phone but
    nobody answers.   CRUNCH!   End of career for both the captain and his
    boss, the squadron commodore, who was on board and in fact gave some
    orders that "helped" the accident.   Fascinating reading:
    frankreed@HistoricalAtlas.net wrote:
    > Lu, you wrote:
    > "But I also have a lot of trouble with the tendency of "experts" to assign
    > "GPS problems" as the reason for any on-the-water incident where the boat
    > was carrying and using a GPS."
    > I agree. It's the "pundit" answer. This incident is also a case where a
    > cheap handheld GPS backup could have made a big difference, not necessarily
    > in saving the boat, but during the rescue.
    > Does anyone know if there is a requirement from any navy or other
    > rule-making body to carry a handheld GPS in a Faraday cage (with backup
    > batteries replaced every six months)? While a sextant might be nice to have,
    > a handheld GPS is smaller, cheaper, easier to maintain and use, much more
    > accurate, and available in all weather. We have all heard reports of GPS
    > "systems" failing, but those are usually integrated charting applications
    > with many sensitive components and the GPS read-out is frequently just a
    > small part. But the loss of all GPS capability aboard a vessel strikes me as
    > bad planning. People carry spare radios to call for help. They carry EPIRBs.
    > Why not spare GPS receivers? Or do they? I understand that some EPIRBs now
    > include GPS positioning.
    > I don't want to stray off-topic here. I'm just wondering about the state of
    > current rules and practice. It strikes me that a rule requiring a sextant is
    > mostly preparing for a disaster with very low probability.
    >  -FER
    > >
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