One way would be to write a simple
plugin that uses the OpenCPN API's
Code:
AddSingleWaypoint(PlugIn_Waypoint *waypoint, bool permament);
GetSingleWaypoint(wxString guid, PlugIn_Waypoint *waypoint);
UpdateSingleWaypoint(PlugIn_Waypoint *waypoint)
to create, retrieve and update a waypoint.
In your
plugin you would need to maintain some sort of reference to the waypoint guid and of course your plugin would need some form of
communications to the outside world , limited by only your requirements, imagination and programming skills.
The only caveat I have, is I have no idea whether OpenCPN adjusts it's active
route if a waypoint's properties (esp. Lat & Long) are changed mid-way.