Question 25 MODU01 - Offshore Installation Manager

The Correct Answer is B **Explanation for Option B (less than 12 meters in length):** International Regulations for Preventing Collisions at Sea (COLREGS), Rule 23 (Power-driven vessels underway), specifies the placement requirements for the masthead light. While generally the masthead light must be placed in the fore and aft centerline, Rule 23(c)(i) provides an exception for small vessels. Specifically, it states that power-driven vessels of **less than 12 meters in length** do not have to comply with the general requirements concerning the placement of lights (Rule 23(a)) and may, instead, comply with the simplified lighting arrangements outlined in Rule 23(d). Rule 23(d) allows the placement of the all-around light (which substitutes for the masthead light and sternlight) at other than the fore and aft centerline if centerline placement is impractical, provided the position is as near the fore and aft centerline as is practicable. **Why the other options are incorrect:** * **A) which has separate sidelights carried on the outboard extremes of the vessel's breadth:** While having sidelights placed on the outboard extremes is common for many vessels, this placement rule for sidelights does not grant an exemption for placing the masthead light off the fore and aft centerline. The masthead light placement requirement is independent of the sidelight placement. * **C) engaged in fishing:** A vessel engaged in fishing must display specific lights indicating its activity, but the requirement for its basic navigation lights (like the masthead light) to be on the fore and aft centerline is generally maintained unless the vessel also falls under a size exemption (like being less than 12 meters). The activity itself does not grant a standard exemption for masthead light placement. * **D) less than 20 meters in length:** This size class (12 meters and up to 20 meters) does *not* qualify for the general lighting placement exemption granted to vessels under 12 meters. Vessels in this category must still comply with the standard Rule 23(a) requirement that the masthead light be placed on the fore and aft centerline, unless specific structures make it impracticable, in which case exceptions apply for placement *above* the fore and aft line, but not generally *off* the centerline. The under 12-meter rule is the primary blanket exemption for moving the masthead light laterally.