Re: On Line Chartplotter??
Since you have a Garmin Chart plotter/GPS system All you really have to do is buy the area that you want to travel through.Not the cartridge but the CD.
Load the CD into your computer and download the area that you want.Now plan everything you want on your computer and once you are done,take the cartridge from your plotter and with the help of a little gizmo that you stick your cartridge in it will down load the area and all the additional info straight from your computer into your cartridge.
You can call the garmin people.They are very helpful and they will explain better than I just did
Good luck.