My understanding is PLB's are not a subscription service, they are pretty much use it if you need it. They only send and SOS and your position. usually can be purchases for about $250 from sporting goods store. Battery usually good for 5 years but might be $150 to replace the battery.
The ones that require subscription are tracking devices such and Inreach or Spot Messenger. What you are paying for is the Active tracking and Messaging service.
Usually the more you pay the more tracking and messaging feature you will get.
definitions.
Tracking - the device actively sends your location and periodic intervals, usually to a website that others can access and see where you are and where you have been. How often it sends your location depends on the service you pay for. Some services may also send altitude information
Messaging - Can vary from a couple preset messages like, I'M OK, Send Help, SOS, to additional pre-programed messages, to send only texting like, Battery Dead Bring Jumper Cables. to a full fledged two way messaging service.
I think of PLB's as emergency devices, they are a lump of lead to carry around and don't do anything for you, until you have an emergency, then they turn into a Brick of Gold, assuming it works.
Tracking/Devices - Cost more but you get more and you are more likely to be carrying it on your belt, rather than having to dig it out of the bottom of your backpack when you need it. And since you use it regularly you have a better feeling that it will work when you need it.
Two way Texting can be invaluable when an accident occurs. Being able to say Attacked by Bear, Bleeding badly, vs just and SOS signal. Or could send something like Broke Leg, but will be ok till morning. Also you can be told Life Flight is on the way as opposed to wondering if they got the message.
Highly recommend viewing:
https://www.aopa.org/news-and-media/all-news/2019/august/02/rps-no-go-around
13 minute mark talks about the Inreach he had and used.
Brian
CFIIG/ASEL
