Next message: Frank Reed: "Re: Role of CN at sea, was RE: Averaging sights ..."
Well, what I really meant was: has anyone heard of a boat loosing or
breaking all of its receivers? At 5 to 10 knots, loosing the signal
for a quarter hour or so shouldn't be a big deal, but loosing all the
GPSs to a lightning strike, simple failure or some series of
accidents could be a big deal, and it seems as if it's bound to happen
sometime.
Nels
On Tue, 12 Oct 2004 19:15:25 -0500, Bill <> wrote:
> > Has anyone ever heard of a vessel loosing all of its GPSs while at
> > sea? If it hasn't happened yet, I suspect it will.
>
> In approx.. 700 hours of land and water operation over the past 3 years, I
> have experienced five loss-of-satellites-signal situations, usually lasting
> from 5-15 minutes. Three were on land, one due to a detour through the
> mountains in Pennsylvania after a 50 car/truck pile up in front of me. With
> mountains on all horizons and a blinding snowstorm overhead, would hardly
> blame that on the system or unit.
>
> The other two land situations I have no explanation for. Great weather,
> flatlands, no military bases nearby.
>
> Of the two on water (Lake Michigan) all units (my Garmin 76, an older
> Magellan, and the owners chartplotter) all failed to get adequate signals
> for 10 minutes or so. Partly cloudy sky. In one case an older Garmin showed
> our speed-over-ground on a broad reach in a 34' Catalina as 33.8 kn. Not
> too shabby--lucky the rudder stayed attached ;-)
>
> I have seen people sit on their unit left on the cockpit cushion and it lost
> all of its waypoints. A friend's older Magellan unit failed to find
> satellites after 3 hours. It is been replaced by a new unit. Have also
> seen two different Loran C units go haywire, with errors of more than 5' lat
> and lon.
>
> In talking with about a dozen sailors on the 600 dock at Michigan City, each
> and every one of them has experienced unexplainable signal loss of 5-15
> minutes while on the water.
>
> Perhaps the Great Lakes don't meet the definition of "at sea," and is mostly
> coastal piloting, but there is ample evidence a single unit can malfunction,
> and even with multiple units, there are periods where signals cannot be
> received.
>
> Not a big deal on the southern half of Lake Michigan where it is pretty much
> point-and-shoot, but uncomfortable in the area where Michigan, Huron, and
> Superior merge.
>
> Bill
>
