Most younger tugboat Mates today only know how to follow the green line on the chart plotter.
They don’t know how to look out the window and navigate by eye.
They might know how to navigate with the radar, but not how to transfer radar ranges or bearings to the chart plotter.
That’s why we still have uncorrected paper charts marked FOR REFERENCE ONLY in the draw. And need Mates that know how to plot a position on paper charts.