Question 3645 Deck General

The correct answer is D) Accidental grounding. According to the regulations for mobile offshore drilling units, a casualty report must be submitted for an accidental grounding. This is because an accidental grounding can potentially cause significant damage to the vessel and the environment, and it is important for the Coast Guard to be informed of such incidents. The other answer choices, such as a man overboard, loss of an emergency generator, or property damage in excess of $20,000, while potentially serious incidents, do not specifically require a casualty report under the regulations for mobile offshore drilling units.