Rampage is correct that only sim card ipads have a built-in gps chip. However, all is not lost if you have a non-sim iPad. I have a quark-a027 which acts as an external gps to a non-sim iPad. It also sends all the boat nmea/seatalk plus AIS data to the iPad or any apple or android phone via WiFi. A further alternative is a Bluetooth gps such as a Garmin glo. I have heard, but cant confirm, that the interns gps in a simmed iPad is quite power hungry, so battery life increases with an external gps, either Bluetooth or WiFi.