Question 29 RVR03 - Mate of LT 500-1600 GRT

The Correct Answer is B Option B, the **alternately flashing red and yellow light**, is correct because it is the specific signal designated in the U.S. Inland Navigation Rules (specifically 33 CFR § 83.35(h)) for use by commercial vessels when they are engaged in public safety activities. This distinctive light signal alerts other mariners that the vessel is involved in urgent public safety missions, such as law enforcement, search and rescue, or fire fighting. *** **Why the other options are incorrect:** * **A) flashing yellow light:** A single flashing yellow (amber) light is typically used in the Inland Rules to designate an **Air Cushion Vessel (ACV)** operating in the nondisplacement mode, or to signal a **vessel constrained by its draft** (though the latter is only mentioned in the International Rules). It is not the prescribed signal for public safety activities. * **C) alternately flashing blue and red light:** While this combination is commonly associated with emergency vehicles (like police or fire trucks) on land, it is **not** the mandated signal specified in the Inland Navigation Rules for vessels engaged in public safety duties. * **D) flashing blue light:** A flashing blue light is specifically reserved under the Inland Rules for use by **law enforcement vessels** when they are enforcing the rules of the road (e.g., conducting a stop or investigation). While law enforcement is a type of public safety activity, the general signal for all commercial vessels engaged in broader public safety (like fire fighting or search and rescue) is the alternately flashing red and yellow light, making option B the more universally appropriate choice for the category "public safety activities."