[GPSNavX]

>> Q1. itouch does not have gps so will have to hook up with say a mac-mini onboard which has a gps fix from a say usb gps. <<

Right so you would need to use WiFi NMEA data for iNavX such as that from a laptop running MacENC.

http://www.gpsnavx.com/iNavX/help/macenc.htm


>> Q2.Does this mean I must use iNavx to run charts and if so will the program display Navionics charts? <<

Yes iNavX can display Navionics charts purchased from X-Traverse..

http://www.fugawi.com/web/x-traverse/navionics_faq.htm


>> Q3. Am I wasting my time here if I need charts for Med and Irish Sea area? <<

No. Navionics charts from X-Traverse has the coverage you need.