MacSailing.net

Just a note of warning that "Airplane Mode" on the iPhone and iPad 3G "Settings" disables not only the cell and WiFi connection, but also disables GPS reception for all apps. Do be sure that "Location Services" in "General" is "ON".

For users concerned with roaming charges, just be sure that "General" "Network" "Data Roaming" is "OFF" in "Settings"

I found this out the hard way in the Bahamas. Since I didn't want roaming charges I set the phone to Airplane mode, and couldn't find my location - no gps at all. Turned airplane mode off and the clock reset, but the time zone wasn't set correctly so AyeTides showed the wrong time. I had to manually set the time zone, find the nearby tide stations, and turn airplane mode back on. Then a week or so later I got an email from a user who went to the Bahamas and had the same problem!