On Fri, 14 Jul 2006 14:15:26 GMT, Cecil Moore
wrote:

Al Klein wrote:
The only thing the GPS-based system does is give you an exact location
- it doesn't notify anyone of anything.

"EPIRB - Emergency Position Indicating Radio Beacons, or EPIRBs,
are used when a ship is in distress, to emit a radio signal
marking the ship's location."

GPS systems are receivers. Transmitters that use GPS-derived data
aren't GPS-based systems, they're transmitter-based systems. No
transmitter, no notification. No GPS, notification is a little less
accurate, that's all.

If radio had not existed, the next passing ship would have
rescued any survivors.

The way it usually was in the centuries before radio (just ask the
crew of the Nuestra Senora de Atocha) was that when the ship sank the
people on her died. (The Atocha's crew were all hardened sailors, yet
only 3 crew members - out of 265 people aboard - clung to the wreckage
long enough to be rescued.)

Yes, that's what I said. Passing ships rescue survivors.

Or, in this case, ships that were part of the same flotilla (they
didn't have to have any luck in being in the area) only managed to
rescue about 1% of the survivors. If they had waited for "passing
ships", their grandchildren would have been too old for rescue. Most
shipwreck survivors who are rescued aren't rescued by ships that just
happen to be passing, they're rescued by ships that knew about the
wreck and responded. (Before radio, most shipwreck survivors weren't
rescued.)