it brings up a point that while you may be hurt so bad or, well...dead that you cant send out a help signal. at least people will know your last check in point and can search from there. better for the family to get the body then never found i think.
Okay, a confession. I laughed through most of "The Revenant". What a load of completely inaccurate bunk. The only thing that I saw in that film that was technically accurate was the part about how quickly a bear can be on top of you. Last fatal bear attack near here involved a guy that was packing a rifle. He didn't have time to fire it.
We live near the mountains here in Calgary, where that film was done. I encounter at least a dozen bears a year on the trails, and about a third are grizzlies. There are stories every year about hikers that just disappear and are lost forever. One of these from a couple of years back was discovered just recently. Without much effort, I can take you to plenty of places where you might see one other person in a whole day on a summer long weekend. People worry about bears, but there are about another dozen critters that will eat you, given the chance. So, timeliness of a rescue can be important, depending on your luck and what stumbles across you if you're down. This would make me think more about a two way feature.
When I was selling satellite phones, a story came back from the high arctic that a crew of scientists landed a helicopter on a frozen lake in winter. When the helicopter completed it's landing, and put it's full weight on the ice, it started to fall through. One guy was beheaded by the prop as the chopper fell through, and two others almost drowned in the icy water. A third guy had the foresight to grab the briefcase sized satellite phone as he jumped out of the other side of the chopper, and managed to get a call in to someone he worked with. The first few minutes the guy at the other end of the call thought it was all a joke. Finally, he realized that this was actually happening, and sent a rescue team to get the three survivors.
Things can change quickly in the wild. Combine an injury with a changing weather pattern and a couple of glowing eyes looking back at you at night...
An accident that I came across on a remote gravel road a decade ago, was a van that somehow had been flipped. I suspect from the damage that it was an end over end, corner to corner kind of roll. The back hatch had opened up, and everything was scattered behind the vehicle. There was one other person who had got there ahead of us, and he had a sat phone, and had called the local RCMP and they were on the way, along with an ambulance. The people in the van looked surprisingly well off. Only the driver had a broken arm.
Now, all that being said, people have been hiking long before satellites, and some simple logic about telling someone where you are going might be a good idea. Also, learning how to read a map and correlate position from either a compass or GPS should be basic, but most people can't. If you break a leg and Smoky T. Bear hauls you back home for the kids, the detailed plan you left with someone about where you are supposed to be won't make for a very complete ending to your story, but you're kind of toast either way.
I think that any of these GPS trackers are great, but they are no substitute for respect for the conditions you are in, an understanding of your capabilities, suitable clothing, good footwear, proper planning, and a good dose of common sense. Carry matches, or a flint, and loud whistle, bear spray, a flashlight, and at least one knife...