Satphone experiences...

Yeah, all those survival skills are a good thing to have but when a hurricane or storm appears unexpectedly and the only guy onboard the boat with sextant skills is down with a broken limb, my idea of self rescue is a pin point sharp GPS and a radio with backup to reach out to whoever's around. SVC Jeff nailed it pretty well for open ocean crossing. No reason not to have this stuff, today, most of it is fairly inexpensive.
Marine radio over telecom works astoundingly well. I was connected from Canary Islands to MN and it was as clear as cell quality. Sorry, nothing to add about satphone.