Ron's a diver and very conscious of safety and always carries a PLB (personal locator beacon), but the day of his near-disaster, the batteries were dead. It was an error that nearly cost him his life. Fortunately, Ron's been interested in lasers since he was a kid and once even had his own laser light show, so for him to carry one in his pocket was normal for him, but not for most people. That laser saved his life, but a PLB would've been a much quicker rescue.
PLBs are much cheaper than they used to be, and IMO, anyone who is ever out of cell phone range should carry one. If you go online and read about the lives saved and the situations they were in, you'll soon realize that you don't have to be extreme to warrent buying one. All it takes is one mistake in a location where you're out of cell range.
The purchase is a one-time deal, as there's no subscription service necessary. When you need help, you simply push a button and your GPS location is broadcast to a number of satellites that are tied into search and rescue receivers. The device costs less than $300 and the only additional cost is sending it in for a new battery about every five or six years for around $150.