When a pushing vessel and the vessel being pushed are rigidly connected, what lights should they exhibit?

When a pushing vessel and the vessel being pushed are rigidly connected, they are treated as a single unit under the COLREGs (International Regulations for Preventing Collisions at Sea). In such a configuration, the combined unit must exhibit the proper navigation lights to ensure safe passage and communication with other vessels.

The correct lighting arrangement involves displaying a masthead light and a stern light. The masthead light, which is white and positioned at the front of the unit, serves to signal the presence of the vessel to others ahead, while the stern light, also white, indicates its presence from behind. This combination of lights is crucial for the safety of navigation, as it provides other vessels with clear and correct information about the vessel's dimensions and heading.

Understanding the lighting requirements helps to prevent collisions and maintains safe maritime practices by ensuring that vessels can be easily seen and identified at night or in poor visibility conditions. The other options do not conform to this requirement, as they do not represent the correct combination necessary for a pushing arrangement.