Hi,
I finally managed to get it working after navionics sent me a new card reader...
It doesn't do live plotting I'm afraid, you'd need to look at PCPlotter for that, or one of the other PC navigation packages that use Navionics charts. There is a section on
www.navionics.com (under Plotters > PC Software) which links to compatible PC plotter packages.
If you are looking for something cheap to cover a relatively small area, admiralty have a package which might do the job.
Fraser