The SeaClear software has a selection option in the same 'box' as AUTOMATIC ON/OFF and TRACK ON/OFF labeled something like SEND NMEA ON/OFF (without gps on my desktop, the label doesn't appear so I don't know exactly what the wording is). When a route is set and activated and the SEND NMEA is ON SeaClear will send the next waypoint (and I assume other nmea data) over the network through the USB to serial converter. The Raytheon converter box that is in the network will convert the nmea to seatalk and the radar display in the cockpit will show the next waypoint. Very nice setup...the laptop stays inside and I have the next waypoint displayed at the helm. All equipment is Raytheon except the laptop and serial/usb converter.
I have been unable to figure how to make OpenCPN software do the same thing.
Hope this helps, but I doubt that I have added much new information here....not sure what else to say.
How do I get OpenCPN to transmit route data/next waypoint?
"Solitude" Caliber 40