Question 27 OSV01 - Master/Chief Mate - Offshore Supply Vessels

The Correct Answer is C ### Why Option C ("sidelights and two towing lights") is Correct This question specifically addresses the lighting requirements for a power-driven vessel that is pushing ahead or towing alongside *on the Western Rivers* (specifically above mile 106.1 on the Mississippi, which is governed by the Western Rivers exception to the International Regulations for Preventing Collisions at Sea, or COLREGs). Rule 24 (c) of the Inland Navigation Rules specifies the lights for a power-driven vessel when pushing ahead or towing alongside on the Western Rivers: 1. **Sidelights:** Required to indicate the vessel's direction. 2. **Towing Lights:** The vessel must exhibit **two towing lights** in a vertical line, instead of the single stern light required under normal Inland or International Rules. These two towing lights are visible from the same arc as a stern light (135 degrees). 3. **Masthead Light(s):** Crucially, the vessel *does not* display any masthead light(s) when pushing ahead or towing alongside on the Western Rivers. Therefore, the required configuration is **sidelights and two towing lights**. ### Why the Other Options are Incorrect **A) one masthead light, sidelights, and stern light** * **Incorrect:** This configuration is generally reserved for a power-driven vessel underway not engaged in towing, or for a vessel towing astern under certain non-Western Rivers conditions. It fails to meet the Western Rivers requirement of two towing lights and incorrectly includes a masthead light. **B) two masthead lights, sidelights, and stern light** * **Incorrect:** This configuration is typical for a power-driven vessel over 50 meters in length that is underway and not towing. It fails to meet the Western Rivers requirement of two towing lights and incorrectly includes masthead lights. **D) two masthead lights, sidelights, and two towing lights** * **Incorrect:** This configuration incorrectly includes masthead lights. A vessel pushing ahead or towing alongside on the Western Rivers does not exhibit any masthead lights.