You can add your own online radio channels in Fishing: North Atlantic, which can be played from the HUD radio or radio in first person.

Go to the Main menu -> Options, and under Game you can add radio URLs for MP3 or AAC.

Enter station name = Name of the radio channel
Enter station URL = MP3/AAC URL of the radio station (Ex. http://simulatorradio.stream/stream.mp3 <- URL has to end with MP3 or AAC to work!)