We asked ourselves this question a few years ago. I couldn't justify the expense of a sat phone - we would end up using it for non-life-threatening purposes and run up a big expense. Also, I would be suspicious that when I really did need to use it the battery would have died. We also didn't want the hassle (and expense) of renting one.
In the end we decided that our primary need was to ensure that if truly had a life-threatening situation we had something that would give us a chance of summoning help. E.g. if we rolled the vehicle in the desert and barely managed to crawl out with broken legs.
As much as I would probably like to be able to receive emails or important calls or update my facebook page everywhere, these things were not of life or death importance. As an exercise I like to think back to the days of global travel before global communication, when someone would kiss his wife goodbye and head by stage-coach for Portsmouth for a ship with words like "look after the children, hopefully I'll be back in 3 or 4 years".
I decided that being able to get mobile phone reception every few days so the phone will pick up any messages as we pass through a zone with signal, was sufficient for non-fatal-emergencies. If we are somewhere that we cannot get a cell phone signal for several days we are probably somewhere it will take multiple days of travel to get home anyway even if a relative is dying.
In the end I settled on a EPIRB / PLB - one that transmits on an emergency frequency and also receives a GPS position which it transmits to satellite.
I know if I am trapped down a slot canyon or in a forest then I may not be able to use such a device effectively, but in many other cases it will work and may be the only thing between me and death.
The EPIRB was a one-off (ish) cost. The battery lasts something like 5 years, after which you must send it back for a new battery (at a cost). But there are no subscription costs.
If I pull the trigger on it the signal will be sent to the coast guard who will try to contact me on the phone number registered with them. If that fails they can alert the relevant rescue authorities (if any exist in the country I am in).
So this works for us and I carry it when travelling or performing risky activities in locations where I am unlikely to get discovered by someone in a few hours. It is small enough and light enough to carry on my person whether hiking or climbing, which also means I am more likely to have it on my person in the event of a vehicle fire, and it is cheap enough that I am less worried about the likelihood of theft. It is also waterproof.
Steve.
'07 Ford Ranger XLT Supercab diesel + '91 Shadow Cruiser - Sky Cruiser 1
'98 Jeep TJ 4.0
'15 Ford Fiesta ST
'09 Fiat Panda 1.2
