That would depend on what you want to save them from.
Most GPSes and chartplotters have a mene function to "save" or "export" routes, tracks, or waypoints. How you do it will depend on the equipment. Usually it is saved to a file, which you can put on your hard drive or elsewhere.
Algarve
The basics is described here over at the opencpn.org site.
It's simple, create your waypoints, or route, save them as a file on your hard-disk, with the extension .gpx, by using the "GPX out" button.
You can now import them to a OpenCPN with "GPX in", at any time, alone or together with other saved files.
Algarve
The basics is described here over at the opencpn.org site.
It's simple, create your waypoints, or route, save them as a file on your hard-disk, with the extension .gpx, by using the "GPX out" button.
You can now import them to a OpenCPN with "GPX in", at any time, alone or together with other saved files.