I looked at this -- I find the idea of a relatively simple device like this, capable of two-way SMS
communications, extremely attractive. If I could send and receive SMS's from the middle of the ocean, that would be, for me, really just as good for all practical purposes as voice comms, and maybe better. All the more since I have
SSB and ham
radio for voice comms.
I found the airtime cost structure for the Delorme device to be very unfavorable, however.
For an alternative, have a look at the Yellow Brick device --
Yellowbrick Tracking - truly global satellite tracking beacons for yacht racing, adventures, treks, expeditions and challenges. This is very cool! Much cheaper to operate than the Delorme, because your airtime never expires, you can switch it on and off as much as you like, and incur no fixed monthly costs when it's off.
If you buy a block of credit for 80 pounds ($130 or so), you can send or receive 1000 (!) SMS's for this (sending a position report is like sending one SMS). That amounts to about 13 cents per SMS -- comparable to what many people pay for SMS's on a mobile
phone system (the main difference being that with Yellow Brick you pay also to receive, not just to send). It costs double to send to a mobile
phone, as opposed to an
email address, but that's still only 26 cents. Line rental is only 8 pounds a month, or about $13, and you can switch it off whenever you're not using it.
This seems like a really killer solution, to me.