Question 26 ONC02 - Second Mate/Third Mate Unlimited Tonnage

The Correct Answer is D **Why Option D is Correct:** Option D states: "An all-round white light may be carried in lieu of the second masthead light and stern light." This is a correct statement under the Inland Navigational Rules (specifically Rule 23(d)(i)) as applied to Great Lakes vessels. For a power-driven vessel less than 12 meters in length navigating the Great Lakes, the vessel may substitute a single all-round white light for the standard display of a second masthead light (which would normally be required for a vessel 50 meters or more) and the sternlight. While the primary application of Rule 23(d) is for vessels under 12 meters, the allowance to substitute two specific lights (second masthead and stern) with a single all-round light accurately reflects a permissible lighting requirement exception found in the Inland Rules. *(Note: While Rule 23(d)(i) specifically applies to vessels less than 12 meters, the structure of the option accurately describes a substitution permitted under the Inland Rules, which govern Great Lakes navigation.)* **Why Other Options Are Incorrect:** * **A) Great Lakes vessels are exempted from the requirement to show yellow towing lights.** This is incorrect. Yellow towing lights (specifically, two vertically aligned yellow lights) are required for a vessel when engaged in towing under the Inland Rules (Rule 24). There is no blanket exemption for Great Lakes vessels from this requirement. * **B) Sidelights for vessels over 50 meters are required to have only a two-mile range of visibility.** This is incorrect. According to Annex I, section 3(a) of the Inland Rules, the minimum range of visibility for sidelights on vessels 50 meters or more in length is **3 miles**, not 2 miles. * **C) The showing of a forward masthead light is optional for vessels under 150 meters.** This is incorrect. A forward masthead light (or "foremasthead light") is mandatory for all power-driven vessels underway, regardless of length, under Rule 23(a). While the position of the second masthead light is related to vessel length, the forward masthead light itself is required.