While cell coverage in a particular area
may not be enough to sustain a voice call,
it may be sufficient to transmit an ~100
byte data packet. Retries might be made
by the software.

The only way to find out for sure anywhere
is by flying the software and observation
of the updated flight path on the ground.

That said there's some giant coverage
gaps in the US West. We won't know until
somebody tries.

At 22:36 09 March 2016,
wrote:
In the West, notably Minden and
Montague cell coverage at altitude is
proba=
bly less than 50 percent (subjectively).
On the ground it is worse, so
no=
t much in the way of emergency service.
My wife follows me on In Reach
and=
loves it. She hated spot. She knows
more than we do.
Dale Bush