We use Navionics Gold on our Raymarine C-series.

You can take the Navionics chart card, put it in a Navionics USB card reader, plug it into a computer and use one of the programs that work with it. I've downloaded a free Raymarine reader (not GPS capable) for use as a a backup if the C-Series goes out. I also downloaded a chart plotter program I can use for free with a 30 day trial period. I haven't installed it yet as it's for backup if the C-Series goes out. I figure that in an emergency situation the 30 days will get me home where I can get the C-Series repaired.

There are a few inexpensive programs you can purchase that plot our position on GPS using Navionics charts.

I like the ability of being able to use the chart card in a number of different machines from dedicated chart plotters to computers.