If you see a red, a green, and a white light on another boat, what does this indicate?

Seeing a red, a green, and a white light on another boat indicates that the vessel is approaching you head-on. In maritime navigation, the red and green lights are navigation lights that help determine the direction a boat is facing. The red light indicates the boat's port (left) side, while the green light indicates the starboard (right) side. The white light is typically used for the stern. When all three lights are visible from your position, it suggests that the other boat is coming towards you directly, as you can see both side lights simultaneously along with the stern light. Being aware of this orientation is crucial for safe navigation, as it helps determine the necessary actions to avoid collisions.