Question 3 ONC03 - Master LT 500-1600 GRT

The Correct Answer is A **Why Option A ("A law enforcement vessel") is correct:** Under the Inland Navigation Rules (33 CFR Subchapter E), a flashing blue light is a specific signal reserved for **law enforcement vessels** when they are actively performing their duties. This signal is used to alert other vessels to the law enforcement presence and operational needs, such as conducting patrols or enforcing regulations. **Why the other options are incorrect:** * **B) A work boat:** Work boats (vessels engaged in dredging, surveying, underwater operations, etc.) typically display specific combinations of shapes and lights (such as red-white-red vertical lights or day shapes) to indicate restriction in maneuverability or the nature of their work. A flashing blue light is not the prescribed signal for a general work boat. * **C) A vessel engaged in a race:** Vessels participating in a race generally follow the standard rules for sailing or power-driven vessels. There is no specific provision in the Inland Rules that mandates or allows a vessel engaged in a race to display a flashing blue light. * **D) A vessel transferring hazardous cargo:** Vessels handling hazardous cargo (if required to signal this status) typically use prescribed warning lights or signals appropriate to their location (such as specific anchorage signals), but a flashing blue light is not the recognized signal for the transfer of hazardous cargo.