BillConner wrote on Aug 13^th, 2013 at 7:01pm:

If you just want to be rescued and have no other purpose or need for a device, get a PLB.  That is all it does and it does it very well - anyplace on earth.  One time cost - 5 years and then replace battery.  Not my choice because my wife wants the I'm OK function.

Couldn't you use a Sat phone with some type of pre-arranged ring to say your OK without having a conversation?
Seems like a SAT phone if you can get one at a reasonable price gives you the most options?