We carry a mobile phone, a sat phone and a PLB in our vehicle. All have gps. They each have a different purpose and a different cost to me. On a 3 year long trip in a vehicle I installed a satellite tracker (pre-spot, reverse gps, to a google map).
I'm older than I used to be, and becoming more cautious with age.
When younger it was sufficient to provide my roughly intended route and if I was overdue by more than a few days someone raised the alarm. I've been late, but never late enough for an alarm.
Now, a rough route and every day update a map through mobile phone, or every couple of days a text with gps coordinates through sat phone that always starts "all ok".
That's the bit that has a bit of planning for possible disaster ... the worst case where the disaster stops all communication, including us being incapable.
The satphone has proven useful for "show stoppers". One was "can you send us a new drive shaft to ..." followed by a three day drive in accompanying vehicle to pick it up. Its also the first stop for "000" ("911" in some countries) or local rangers (you do carry their numbers don't you?).
Importantly (for me) the satphone also allows family to call (cost of a mobile call and free to me) with ********-chat or their emergencies .... that happened and we could judge whether to halt the trip.
My vehicle based trips tend to be more than a couple of months, and have sufficient planning that I can stop the satphone subscription when not in use and simply restart when required. A bit of a pain but I dislike paying for something that's not in use. I tried pre-paid, and made sure I could recharge through the phone. Now I pay for calls/texts - cost doesn't seem to matter when its the only form of communication.
Another approach I've seen, and experienced on a recent desert trip, was daily HF radio calls to check in. Australia has some vary tall aerials and monitoring. Interestingly when a recent sched was missed we resorted to sat phone for coordination of efforts and following vehicle tracks - fortunately a false alarm.
We refer to our daughter as our "remote area support coordinator". An interesting set of skills that requires some imagination and initiative. Capable of making decisions and taking actions on our behalf. A single point of contact. Nothing worse than being on hold on a satphone.
The PLB is last resort. For just the reasons mentioned. Its only one way. I'd really hate for the helicopter or ground party to turn up with the wrong equipment.
Not only is one way communication a problem for SAR its also a problem for me. Two way communication allows me to describe the situation, which means better quicker decisions, better more targeted response, and possibly faster response for that really immediate life threatening occasion I hope never happens.
The one-way tracker on our 3-year trip was useful for family and friends but also created a problem. It needed a bit of education to interpret whether we had stopped because we liked a place or stopped because we had a problem. No-one ever called emergency, but there was a bit of worry at times. I guess there's a different SAR approach for calls from a "site" or calls from "support". Calls from support have much more uncertainty, the less uncertainty the better for SAR.
Different devices, different purposes, and maybe someday someone will integrate them "properly" and cost effectively. I think Spot and Inreach are filling a gap which will be closed.
