Question 23 RVR04 - Master or Mate of LT 200 GRT

The Correct Answer is C 1. **Why option C ("a vessel of special construction") is correct:** Rule 21(a) defines the masthead light. Rule 20(b) (Application) and Rule 1(e) (General) both permit exceptions for lights and shapes when necessary for vessels of special construction or purpose. Specifically, Rule 1(e) states: "Whenever the Government is satisfied that a vessel of special construction or purpose cannot comply fully with the provisions of any of these Rules with respect to the number, position, range or arc of visibility of lights or shapes, as well as to the disposition and characteristics of sound-signalling appliances, such vessel shall comply with such other provisions in regard to the number, position, range or arc of visibility of lights or shapes, as well as to the disposition and characteristics of sound-signalling appliances, as her Government shall have determined to be the closest possible compliance with these Rules in respect of that vessel." This allows the masthead light (which is generally required to be on the centerline, as per Rule 21(a) and Rule 2(a)) to be displaced if the vessel’s structure makes centerline placement impossible. 2. **Why the other options are incorrect:** * **A) a vessel engaged in trolling:** A vessel engaged in trolling is typically displaying lights for a vessel engaged in fishing (Rule 26). While fishing lights are specific, they do not inherently grant permission to displace the required forward masthead light from the centerline unless the vessel also qualifies under Rule 1(e) as being of special construction. Standard fishing vessels must adhere to the positioning rules where possible. * **B) a power-driven vessel 12 meters in length:** Rule 23 details the lights for power-driven vessels. A vessel 12 meters in length is a small vessel and is required to follow the standard positioning rules for the masthead light, which mandates centerline placement (Rule 21(a) defines the masthead light position relative to the fore-and-aft centerline plane). * **D) an air-cushion vessel in non-displacement mode:** An air-cushion vessel (hovercraft) is subject to specific lighting requirements (Rule 23(b)), requiring an all-round flashing yellow light in addition to standard power-driven vessel lights. While its speed and operation are unique, its required power-driven vessel lights (including the masthead light) must still comply with the standard positioning requirements, meaning the masthead light should remain on the centerline unless an exemption under Rule 1(e) is specifically granted due to its construction.