holmes4:
The only one I can think of is mobile phone (Gsm) type tech.WiFi, far to short range (about /100 or 1/0000) of the range you need.
XBee's are near to the range you want but still a factor of ten ( I think off).
So yes am be mobile phone tech may do it, but this could depend on the local mobile coverage.
Satellite phone may be the best option.
I'll try to find the link, but there is a web site about and competition to get an automatic/robot boat across the Atlantic. One of the rules is that it must report daily by satellite once a day.
Mark
what do you mean by the factor of ten with the xbee?
i was thinking of using xbee rather than gsm because of the coverage issue, not that i fish many beaches without coverage
satellite sounds costly
that competition sounds cool I recon my boat would have to be in the running if you could hook the batteries up to a solar panel