FWIW, I would think something like the Garmin Astro dog tracking system would be much better technology (yes, more expensive) for this type of issue. Strap one of these puppies to the top of everyone's pack, and off you go.

The gotcha is the use of line-of-sight radio, which adds a serious limitation.

I'd love to see something like the Garmin Astro, but with some sort of satellite packet data for the updates.

Heck, if you had something like that, and then added an emergency button on it, you could have quite an effective tool for hikers, SAR, wilderness firefighters and even tracking your dogs while out in the woods.

-john