I've tried creating a route in OpenCPN and saving it in the Garmin .gpx format, but when I load it onto a chip and try to import the route in my chartplotter it does not show up.
Yes, I've done it with a Garmin echoMAP 54cv and a Garmin GPSMAP 400/500 series. Garmin has two file formats for routes, GPX and ADM. Be sure you select the GPX format when you want to see files from OpenCPN.
1 Select Nav Info > User Data > Data Transfer > File Type.
2 Select GPX.