When shall the white flashing lights on an oil rig be exhibited?

The correct answer is that white flashing lights on an oil rig shall be exhibited from 15 minutes before sunset until sunrise and anytime visibility is 2 miles or less in any direction. This requirement is based on the need to ensure proper visibility and safety in navigational areas, especially for vessels operating near the oil rig.

The regulation aims to prevent collisions and enhance the awareness of the oil rig's presence, particularly during times when natural light is diminished or visibility is restricted. By requiring these lights to be displayed both during low-light conditions (such as at night and during sunset) and during periods of poor visibility, the risk of accidents is significantly reduced.

Other options do not meet the necessary criteria for safe navigation. For instance, exhibiting lights only during the day would not adequately warn vessels during critical evening and nighttime hours. Displaying lights at all times may cause unnecessary light pollution and could lead to confusion since the lights are specifically intended for certain visibility conditions. Lastly, limiting the exhibition of lights to only inclement weather fails to account for regular nighttime operations or adverse visibility conditions that can occur even in clear weather.