Firstly I don't think a Sat phone would give the same degree of "Safety" than a EPIRB - or simular device.
As they say a mobile phone is no substitute for a VHF radio.
A sat phone would be OK to raise the alarm, but no good for the rescue teams to home in on you - how long do the batteries last in the Sat phone.
Anyway.... Back to Sat phones....
Iridium - Truely global coverage - the reports from Spririt of Cardiff are all by Iridium so we know it works.
Andy had a "new" handset he was trying to sell - I'm not sure if he still has it
The monthly line rental is supprisingly low - $15
The new design of handets are much smaller than the original ones
Websites - www.iridium.com www.marconi-marine.com/iridium/
I've not heard of Thuraya before - looking at their web site tere is no coverage in America - so its not global (your bound to have a problem out of coverage!!)
Iridium handsets could originaly "roam" between GSM networks and the Iridium Satalite network - what this meant that most of the calls went over GSM, making not much money for Iridum, they then went broke, but it was such a good satalite system that it was rescued and now runs as a Satalite only network (no roaming)
If Thuraya are alowing roaming on GSM I wonder if they will have the same problems!
Just a couple of comments!