And, there's more!
The IridiumGo also has a dedicated SOS function. Even if you did not have access to a phone or tablet the IridiumGo on its own can send a distress call. Without another device, you would not have two way communication, but you WOULD have a SOS message with location and with confirmation sent that would backup the EPIRB signal with the SAR authorities.
Great Guana Cay, Abacos, Bahamas