What does the red over white light configuration indicate at night?

The red over white light configuration at night indicates a vessel that is fishing. According to the International Regulations for Preventing Collisions at Sea (COLREGs), when a fishing vessel is engaged in fishing, it is required to display specific light configurations to communicate its activity to other vessels.

The red light signifies the vessel's fishing status, while the white light helps to illuminate its presence. This arrangement alerts other mariners that special navigational considerations may be necessary due to the fishing activity taking place. This is important for safety and navigational awareness in waters where multiple types of vessels may be operating simultaneously.

Understanding these light configurations is crucial for avoiding collisions and ensuring safe navigation, especially in busy maritime environments where fishing operations are present. The other options, while relevant to different circumstances, do not utilize the red over white light configuration, which is why this choice is the one that best reflects the correct interpretation of the signals.