Current diagrams - app or plug in?

[ramalkin]

I frequently sail in a river with significant current.
There is no current diagram in the NOAA Tidal Current
Tables for my sailing area (Cape Fear River).
So, I generated a current diagram and speed lines
to predict the best times for departure and transit time.

However, it seems like there should be a simple app or program
(Open CPN plugin??)
that can provide an accurate route planning in a tidal
river.

Does anyone know of such an app or plugin?