I'm just putting this here for the New Idea area, in case you run out of things to do.
With a NMEA 2000 driver I could display things like course and speed and time to destination on a scene. Probably not many people using myserver on a boat, but I figured I toss it out there.
With a NMEA/IP gateway the NMEA traffic shows up as UDP broadcast packets that you would need to listen for an put into variables. Maretron makes the high end stuff if you're looking. But it isn't meant to control entertainment systems and I don't think I've ever seen an entertainment system with telemetry from the boat.
I don't realistically expect it and though possible, I doubt many people would want to control course and speed while laying in bed watching a movie. It would just be a cool thing to show to passengers.