One of the readers of this blog recently made a comment that leads me to believe I need to clarify the function of a PLB or SPOT Satellite Messenger.
What the reader said was that he doesn't go places where he is likely to get lost — as if I had somehow given the misconception that the SPOT is merely a GPS device. It isn't. That is not its function. This is a device that can notify either your friends/family that you are OK on your journey, to alleviate their worry, or to show them your GPS coordinates through a tracking mode so they an see your progress as you travel, or (and this is the big OR) to call in the search and rescue team if your life somehow becomes at risk.
I don't use my SPOT to keep track of where I am. I use it to let others keep track of where I am. I still use a map and compass, common sense, dead reckoning navigation techniques, and occasionally I'll pull out my GPS to verify my coordinates and mark them on the map. For me, the joy of the backcountry is in the simplicity. But in this day of inexpensive and reliable technology, there's no reason not to have a backup system that can save your life.
After all, I never made a parachute jump that didn't also include a reserve chute. Only had to use it once, but on that day I was mighty happy I had it.