At what height shall the white flashing lights on an oil rig be placed?

The correct answer indicates that the white flashing lights on an oil rig should be placed at a height of not less than 6 nor more than 30 metres. This specification is crucial for ensuring the visibility of the lights to other vessels, thereby enhancing safety in maritime navigation. By establishing a minimum height of 6 metres, it assures that the lights are above potential obstructions in the surrounding water or on the rig itself, while the maximum height of 30 metres helps ensure that they are prominent enough to be seen from significant distances, especially in the dark or during poor visibility conditions.

The height range outlined in this answer complies with the standards set by the International Maritime Organization (IMO) for offshore structures, which aim to reduce the risk of collisions by providing clear visibility of lighting signals to approaching vessels. Proper placement of these lights is vital in maritime operations, as it warns nearby ships about the presence of the rig and indicates potential hazards.

In comparison, other height ranges provided in the incorrect answers may not sufficiently meet the visibility requirements or may not accommodate various maritime conditions, making them unsuitable for ensuring safe navigation around oil rigs.