Final answer:
The lights for a pilot vessel on duty underway include a masthead light, sidelights, and a stern light.
The lights for a pilot vessel at anchor include an all-around white light and vertical red and green lights.
Step-by-step explanation:
A pilot vessel on duty will display an all round white light over an all round red light.
The lights for a pilot vessel on duty underway and at anchor serve to signal its position and intentions to other vessels. The lights on a pilot vessel on duty underway consist of a masthead light, a sidelight, and a stern light.
The masthead light is white and is visible from all directions. The sidelights are red on the port side and green on the starboard side, and they are visible from dead ahead to 22.5 degrees abaft the beam. The stern light is white and is visible from dead astern to 67.5 degrees abaft the beam.
On the other hand, the lights on a pilot vessel at anchor consist of an all-around white light at the masthead, visible from all directions.
Additionally, there may be two red lights and two green lights, mounted vertically, to indicate the vessel's presence at anchor during restricted visibility. These lights are visible from dead ahead to 67.5 degrees on either side of the vessel's bow.