I have a big problem.
I have a USGlobalSat ND-100S GPS Receiver (USB dongle) with aN Apple Mac Book Pro. I am looking for Mapping software that works with both of the above and Garmin vector maps (IMG, GDB) as well as Google Maps & Earth.
I am travelling in Africa and want to use Olaf Maps (IMG) as well as other off-road tracks created by other users (mainly Garmin format)

The ideal mapping software would be Garmin Basecamp but I can't afford a Garmin GPS. The other option is Ozi Explorer but only works for PC (have tried to get VirtualBox working but don't have windows). Route Buddy doesn't seem to work with any other maps but its own and MacGPSPro doesn't work with vector maps.

Is there a solution? Or do I either need to buy a Garmin device and use Basecamp or buy a PC laptop? Neither of which can I afford.

Or can I convert IMG and GDB maps to a format that MasGPSPro can read?

Please help urgently.... hitting western sahara tomorrow and need to find a solution, or else staying onthe tarmac!!!