Currently it is not supported directly on the IO pins, you will have to connect it to a computer (or Raspberry Pi) and use our Python script to send it over HTTP: https://github.com/waterlinked/examples/blob/master/nmeainput.py.

This is a great idea and we would like to support this in the future.
Any thoughts on what kind of connector would be convenient for connecting an external GPS to the Underwater GPS?