Question 3 ONC04 - Mate of LT 500-1600 GRT

The Correct Answer is A **Explanation for A (A law enforcement vessel):** In the Inland Waterways Safety Rules (which correspond to the Inland Navigation Rules, specifically Rule 22 and associated Annexes), a flashing blue light is a unique signal reserved exclusively for a **law enforcement vessel** operating in the capacity of law enforcement. This light identifies the vessel as an official agency authorized to enforce laws, regulations, or treaties. **Explanation why other options are incorrect:** * **B) A work boat:** A vessel engaged in work (like dredging, towing, or maintenance) typically displays special shapes or lights such as all-round white, red, and/or green lights (e.g., restricted in ability to maneuver lights), but not a flashing blue light. * **C) A vessel engaged in a race:** There are no specific Navigation Rules lights or shapes mandated for recreational or racing vessels that would involve a flashing blue light. Racing vessels follow standard rules for power-driven or sailing vessels. * **D) A vessel transferring hazardous cargo:** A vessel carrying or transferring hazardous cargo does not display a flashing blue light. Such vessels must comply with standard carrying and towing rules and may display specific warnings or markings required by organizations like the Coast Guard or DOT, but not a blue flashing light as a navigation signal.