This is not a question, but a "works with" report.
With some tweaking I got
OpenCPN 4.4.0 working with a
Garmin GPSmap 62s and Windows 10 Pro x64 (on a Dell Latitude E7450) over a USB-cable.
You need
Garmin Spanner
software (I think it is just a driver) from here:
https://www8.garmin.com/support/download_details.jsp?id=1627 There is a warning that it is not supported on Windows Vista and later and indeed the installer smells very Windows 2000, but it works for me on Windows 10 without any compatibility settings.
On the
GPS you need to set: Menu > MainMenu > Setup > System > Interface: Garmin Spanner. Do this before you
plug in the USB cable.
Restart the
GPS and
plug in the USB cable. You should get the question: "USB cable detected. Would you like to go to Mass
Storage?" Select and enter No.
In
OpenCPN go to Option > Connections. Add a new connection with these properties:
Serial, DataPort: Garmin-USB, Baudrate 9600, Priority 1.
In my case the following was already selected and I did not change them: Protocol
NMEA 0183, Control Checksum, Use Garmin (GRMN) mode for input, Accept only sentences, Transmit sentences.
The GPSmap 62s is a device for landlubbers, but even without OpenCPN it has some nice
marine features like
Anchor Drag
Alarm.