GPSNavX displays raster charts; not compatible with Navionics vector charts from Fugawi.com
Article MA15129, June 4, 2018
GPSNavX is not programmed to display Navionics vector charts. To view Navionics on a Mac, use the software MacENC.
The design of GPSNavX is for displaying raster (static picture) charts -- and it does this very well along with many other features for marine navigation. But this software does not import and display Navionics charts (which are vector graphics files). Either you will need to source raster charts of the areas you boat in and load those into GPSNavX, or if the Navionics charts are the only choice for your needs then you need to get the MacENC software manufactured by the same company that produces GPSNavX.
For MacENC users, Navionics charts are for sale through the Fugawi web store.