The cost for text messaging by satellite is cheap these days, paying less than at@t cell data plan and its in the iridium network, pole to pole. There is also a lower cost Globalstar Spot connect, around 9 bucks.
It pairs up with your iphone by bluetooth, though somewhat clunky to set up but when u get the hang of it, its better than a 406 plb. 😀
When was the last time you went fishing, hiking, climbing and there was no cell coverage, what u gonna do when TSHTF?