Of the required ring life buoys for a MODU, how many must be equipped with a water light?

Correct Answer: Option C — 4

Title 46 CFR 108.565 specifies that at least four of the required ring lifebuoys on a Mobile Offshore Drilling Unit must be equipped with self-igniting water lights. These lights automatically illuminate upon floating in water, marking the buoy's location to assist in man-overboard recovery during nighttime operations.