On Sep 8, 12:02*pm, "Roger Long" wrote:
Yes, SPOT uses its GPS for position and then sends the position over the
Iridium network. *I'm not familiar with the Sat phones and it never crossed
my mind that they would provide position information. *According to Zac's
parents, the Iridium rep told them that they can determine position from the
call records and this information is often used for SAR.

Sure, they use low Earth orbit sat's so they need to have some kind of
idea of how to pass you from sat to sat as they go overhead. Cell
phones use a similar trick and also know, more or less where you are
at even w/o GPS. Iridium phones do not AFIK use gps for this so the
position is less accurate than a gps pos would be and would not have a
consistent accuracy.


It was the far off course position that put Zac in a dangerous area that
panicked his parents, not just the silence. *Possibly a units mix up as you
say but Zac's parents are professional yacht delivery people so it doesn't
seem highly likely. *

And yet, I hear pros making this mistake a lot. The CG uses dd mm.mm
format and I have heard CG controllers screwing up positions reported
in dd.dd and dd mm ss format. Who knows. I was just throwing it out
as a possibility.

I find the reactions to this voyage quite amusing. *On the one hand are the
nay sayers who claim it is irresponsible to have let one so young go out on
the big ocean alone. *On the other hand are the ones who say his parents are
exerting too much control and oversight. *Where in the middle is the
microslice of appropriate parenting?

Please Roger, 99.9999999...% of parents would not let their kids do
this. We're so far out of the normal bounds of appropriate parenting
that they probably don't provide any useful guidance. I don't feel
that I'm in any position to second guess their decision to send the
boy off. But, having decided to let Zac do this thing they will have
to work with the reality that he will be out of contact from time to
time. As he approaches the Indian Ocean his HF nets will get thinner,
the cruising community smaller and the SAR less available. He will be
out of contact and errors in position will come up. If his folks
can't allow him to be out of contact for long enough for these things
to work themselves out then they are in for a very hard time. If
nothing else, requiring twice a day reports greatly increases Zac's
workload and when he gets tired the priority will be working the boat
and the pos reports will just have to wait.

-- Tom.