Hello, I have finally success ! For other people who want to know how I do this, You must override methods : Setpositionfixex (for pointer of boat
position) and add event "WANTNMEA event. Also, you need to catch a pointer of graphic context of openCPN
and also viewport pointer with the method renderoverlay. Finally, I have a strange problem, when my plugin is launch, there is my text next to the bot and is Ok, but when i go on Option of opencpn in "plugin", i don't see my plugin, and when i click on "Apply" my text disapear so it's bug... Did I forget something ? In DeInit method maybe ? Have a nice day !