Question 23 RVR03 - Mate of LT 500-1600 GRT

The Correct Answer is C. ### Why Option C is Correct: **C) a vessel of special construction** The rules governing the placement of lights (specifically the COLREGs, Annex I, Section 3(a)) include provisions for vessels where strict compliance is impossible. This exception states that if it is impracticable for a vessel of **special construction or purpose** to comply fully with the provisions of Annex I regarding the placement of lights, the lights must be placed as closely as possible to the prescribed position. This impracticality often relates to the masthead light being displaced from the vessel's centerline due to inherent structural design (e.g., certain tugs, survey vessels, or icebreakers). Therefore, a vessel of special construction is explicitly permitted to have its masthead light displaced if necessary. ### Why Other Options Are Incorrect: **A) a vessel engaged in trolling** A vessel engaged in trolling is simply a fishing vessel. While fishing vessels often have specific light configurations, the general rule requires the masthead light (or the all-round white light if under 50 meters) to be on the centerline unless otherwise specified. Engaging in trolling does not grant a blanket exemption for displacing the masthead light from the centerline. **B) a power-driven vessel 12 meters in length** A power-driven vessel of 12 meters in length is a small vessel. Per COLREGs, the masthead light (or the combined lantern) must typically be placed on the centerline. There is no provision that allows a standard small power-driven vessel to displace its masthead light merely due to its length. **D) an air-cushion vessel in non-displacement mode** An air-cushion vessel (ACV) operating in non-displacement mode (flying/hovering) must exhibit specific lights (an extra all-round yellow flashing light), but the standard navigational lights (masthead lights) must still comply with the centerline requirement, just like any other power-driven vessel, unless it also qualifies as a vessel of special construction that makes compliance impossible. The ACV status itself does not grant the exemption for displacing the masthead light from the centerline.