Rules of the Road: BOTH INTERNATIONAL & INLAND When may a pilot vessel continue to sound an identit...

A pilot vessel can identify itself as a pilot vessel anytime it is engaged in pilot duties. It' possible that a pilot vessel at anchor is still engaged in pilot duties.
Answer A - A vessel NUC would sound 1 long and 2 short.
Answer B - A vessel no longer on pilot duty is simply a powerboat
Answer D - a vesel aground sounds 3 bells, 5 bells, 3 bells (and gong if 100m or more)