Final answer:
Vessels operating between sunset and sunrise must have navigation lights, including a red light, green light, white light, masthead light, and all-round white light.
Step-by-step explanation:
When operating between sunset and sunrise, vessels must have certain devices on board to ensure safety and navigation. One of the most important devices is navigation lights, which help other vessels determine the position, direction, and size of the vessel. These lights include a red light on the port (left) side, a green light on the starboard (right) side, and a white light on the stern (back) of the vessel. Additionally, vessels must have a masthead light, which is a white light visible from all directions, and an all-round white light. These lights allow vessels to be seen and avoid collisions in low light conditions.