Question 25 GLI02 - Mate of Unlimited Tonnage

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 regarding lights and shapes (e.g., COLREGs Annex I, Positioning and Technical Details of Lights and Shapes, which is referenced in U.S. Inland Rules). Rule 21(a) in Annex I specifies that: > The masthead light or after masthead light, as the case may be, shall be placed in front of the forward half and not more than half the vessel’s length from the stem. However, Annex I provides exceptions for smaller vessels. Specifically, section 3(b) states that for a vessel **less than 12 meters in length**, the masthead light may be placed **off the fore and aft centerline** if the practical placement on the centerline is not possible, *provided* the sidelights are combined in one lantern on the fore and aft centerline. If the sidelights are separate (as is usually the case), the rule allows the masthead light to be off-center on vessels less than 12 meters if necessary due to construction, as long as the offset placement does not interfere with the proper functioning or observation of the other required lights. The key exception that allows a masthead light to be placed off the fore and aft centerline applies specifically to power-driven vessels **less than 12 meters in length**. **Why other options are incorrect:** * **A) which has separate sidelights carried on the outboard extremes of the vessel's breadth:** While the placement of sidelights is relevant, the general rule for all vessels is that the masthead light must be located near the fore and aft centerline. Having separate, properly placed sidelights does not automatically grant an exemption for the masthead light to be placed off the centerline. The specific exception for off-center placement is tied to vessel length (less than 12m), not the type of sidelights (unless the sidelights are combined in one lantern, which creates a different set of placement constraints). * **C) engaged in fishing:** A vessel engaged in fishing displays specific lights (all-around green over all-around white) in addition to or instead of the masthead light, but its designation as a fishing vessel does not grant an exception regarding the placement of the standard masthead light (if carried) relative to the centerline. This rule is length-based, not activity-based. * **D) less than 20 meters in length:** While vessels less than 20 meters receive several lighting exemptions (such as being able to carry only one masthead light instead of two, and exemptions regarding vertical separation), the specific exception allowing the **lateral** placement (off the fore and aft centerline) is reserved for vessels **less than 12 meters** in length (Annex I, 3(b)). Vessels between 12 and 20 meters must adhere to the centerline placement requirement for the masthead light.