Question 29 RVR04 - Master or Mate of LT 200 GRT

The Correct Answer is B Option B, **alternately flashing red and yellow light**, is correct because the Inland Navigational Rules (specifically 37(a)(iii)) prescribe this visual signal for a commercial vessel engaged in public safety activities. Rule 37(a)(iii) states that a vessel engaged in law enforcement or public safety activities, operating on the navigable waters of the United States and not at anchor, may display an alternately flashing red and yellow light signal. **Why the other options are incorrect:** * **A) flashing yellow light:** A single flashing yellow (or amber) light is typically used in the Inland Rules to designate a high-speed craft (WIG or hydrofoil) when operating in the non-displacement mode, or for an air cushion vessel (ACV). It is not the prescribed signal for public safety activities. * **C) alternately flashing blue and red light:** While blue and red lights are commonly associated with emergency vehicles on land, this specific alternating combination is not the internationally or federally prescribed visual signal for marine public safety activities under the Inland Rules. * **D) flashing blue light:** A single flashing blue light is typically reserved for use by law enforcement vessels, generally when engaged in enforcing laws. While a component of enforcement is public safety, the specific signal prescribed for general *public safety activities* (as opposed to strict law enforcement) is the alternating red and yellow light.