The correct answer is D) extinguishment of Robbins Reef Light in New York City's Upper Bay. A HYDROLANT is a navigational warning issued by the U.S. Coast Guard to alert mariners to important or urgent maritime safety information. Typically, HYDROLANT warnings are sent for hazards to navigation, such as the presence of large or unwieldy tows, unexploded ordnance, or other obstructions in the water. However, the extinguishment of a specific navigation light, like Robbins Reef Light, would not normally warrant a HYDROLANT warning, as this information would be more appropriately disseminated through other channels, such as Local Notices to Mariners. The other answer choices, such as a report of an overdue ship or the presence of a large tow in congested waters, would be the types of situations that would typically trigger the issuance of a HYDROLANT warning to ensure the safety of all vessels in the affected area.