Look for an “Export” or “Save As” function (I don’t have the Navionics software either but know that it can be done as others have done so). Ideally you want to save or export them in the GPX file format. You can than open the GPX file in HumminbirdPC and upload the waypoints to an SD memory card. Once on the memory card you can power on your 788ci unit and install the memory card – the unit should automatically load the waypoints.