[GPSNavX]

Either scenario works the same as far as iNavX is concerned. All iNavX needs is an IP address and a port to receive AIS NMEA data.

MacENC can be setup to be a server for NMEA data over IP..

http://www.gpsnavx.com/MacENC/help/connectingtcp.htm

So you would connect the AIS receiver to your Mac, then use MacENC to broadcast the NMEA data.

In order to make a 'public' server you could connect anywhere you had a cell connection you would need a static IP address.