Question 26 OSV02 - Mate - Offshore Supply Vessels

The Correct Answer is D ### **Explanation of Correct Option (D)** **D) An all-round white light may be carried in lieu of the second masthead light and stern light.** This statement is correct based on the Inland Rules (33 CFR Subchapter E). Inland Rule 23(d) provides special provisions for small vessels. Specifically, for power-driven vessels less than 12 meters in length, the rules permit them to show an all-round white light in lieu of the standard masthead light and stern light, provided they also show sidelights. This flexibility is extended on the Great Lakes and Western Rivers, where power-driven vessels less than 20 meters may also utilize this all-round white light option (33 CFR 89.17). Therefore, for smaller vessels operating in the Inland/Great Lakes area, the all-round white light simplifies the lighting requirement by replacing the two separate lights (second masthead and stern light), making this option correct. *** ### **Explanation of Incorrect Options** **A) Great Lakes vessels are exempted from the requirement to show yellow towing lights.** **Why it is Incorrect:** Yellow towing lights are mandatory under Inland Rule 24 for any vessel towing astern. A vessel towing astern must show two (or three) masthead lights, plus a stern light and a **towing light (yellow)** shown above the stern light. Great Lakes vessels are not exempt from this requirement. **B) Sidelights for vessels over 50 meters are required to have only a two-mile range of visibility.** **Why it is Incorrect:** Inland Rule 22 (Visibility of Lights) mandates that sidelights for vessels **50 meters or more** in length must have a minimum range of visibility of **3 nautical miles**. The two-mile requirement applies only to vessels between 12 and 50 meters. **C) The showing of a forward masthead light is optional for vessels under 150 meters.** **Why it is Incorrect:** Inland Rule 23 requires that all power-driven vessels 12 meters or more in length must show a forward masthead light. This light is mandatory, not optional. The 150-meter threshold relates to specific positioning requirements for the lights, not whether the forward light must be shown.