Final answer:
If your power boat is less than 39.4 feet long and you are underway at night, you need to display a white masthead light, a green light on the starboard side, and a red light on the port side. If your boat is less than 23 feet long, you also need to display an all-around white light when anchored or drifting.
Step-by-step explanation:
If your power boat is less than 39.4 feet long and you are underway at night, you are required to display specific lights to ensure the safety of yourself and other boaters. According to the International Regulations for Preventing Collisions at Sea, you need to display a white masthead light at the front of your boat, a green light on the starboard (right) side, and a red light on the port (left) side. These lights help other boaters determine your position and direction of travel, reducing the risk of collisions.
Additionally, if your power boat is less than 23 feet long, you are required to display an all-around white light when anchored or drifting. This light helps other boaters see that your boat is not moving and prevents them from running into you.