[GPSNavX]

Make sure you install the Keyspan OS X driver for your version of OS X.

Keyspan Drivers

Plug the Keyspan adapter in to your Mac's USB port

Plug the Garmin GPS into the Keyspan adapter

Make sure your Garmin GPS is in and set to transmit NMEA out

Start GPSNavX

Select "Connect" on the "GPS" menu

Select "Settings" button to open the Settings drawer

Select type 'Garmin'

Select port /dev/cu.KeySerial1

Select rate 4800

You should then see the UTC field of the GPS panel updated


If you don't want to mess around with all this then order the BU-353 USB GPS..

BU-353 UBS GPS