Question 25 MODU02 - Barge Supervisor

The Correct Answer is B **Explanation for Option B (Correct Answer):** The placement of navigation lights, including the masthead light, is governed by the Rules of the Road (specifically, the International Regulations for Preventing Collisions at Sea (COLREGS) or equivalent national rules like U.S. Inland Rules). Rule 23 (Power-driven vessels underway) and Annex I (Positioning and Technical Details of Lights and Shapes) provide specific exemptions for smaller vessels. Annex I, Section 3(a) generally requires that "masthead lights... shall be placed in the fore and aft centerline of the vessel." However, Annex I, Section 3(b) provides an exemption: **"On a vessel less than 12 meters in length, the masthead light or all-round light may be placed off the fore and aft centerline if impractical to carry them on the centerline, provided that the sidelights are combined in one lantern which shall be carried on the fore and aft centerline of the vessel or located as nearly as practicable in the same fore and aft line as the masthead light or the all-round light."** Therefore, a power-driven vessel less than 12 meters in length has specific provisions allowing the masthead light to be located other than on the fore and aft centerline if necessary due to the vessel's small size and layout. **Explanation for Incorrect Options:** **A) which has separate sidelights carried on the outboard extremes of the vessel's breadth:** While vessels of significant length often have separate sidelights placed outboard, this arrangement does not automatically grant permission to move the masthead light off the centerline. The primary requirement for the masthead light's centerline placement still applies unless the vessel meets the length exemption (less than 12 meters). **C) engaged in fishing:** The type of activity (like fishing, towing, or sailing) determines *which* lights must be displayed (e.g., all-round green and white for fishing), but it does not generally change the mandated *positioning* (fore and aft centerline) of the standard masthead light for power-driven vessels, unless the vessel is also less than 12 meters in length. **D) less than 20 meters in length:** While vessels less than 20 meters receive several concessions regarding light positioning and visibility, the specific rule allowing the masthead light to be placed *off the fore and aft centerline* is restricted to vessels **less than 12 meters** in length (Annex I, 3(b)). Vessels between 12 and 20 meters must still adhere to the centerline placement for the masthead light.