Question 46 RVR05 - Master of LT 100 GRT

The Correct Answer is A **Explanation for A (Correct Option):** Option A ("The vessel's lights must comply as closely as possible.") is correct because it reflects the exception provision found in the Inland Navigation Rules, specifically Rule 2(b) concerning the responsibility for compliance. This rule acknowledges that certain vessels, particularly those built before the effective date of the rules or those determined by the Secretary to be incapable of full compliance with structural requirements (like masthead light spacing), are grandfathered or excused from full compliance. In such cases, the rule requires the lights to comply *as closely as possible* to the requirements, provided the Secretary of the department in which the Coast Guard is operating has determined that full compliance is impracticable. **Explanation of Incorrect Options:** **B) The vessel must be altered to permit full compliance with the rules.** This is incorrect. While full compliance is generally required, the premise of the question is that the Secretary has *already determined* that the vessel cannot comply with the spacing requirement. Requiring alteration when the Secretary has deemed compliance impracticable defeats the purpose of the exception rule. **C) An all-round light should be substituted for the after-masthead light and the stern light.** This is incorrect. Substitution of lights (like replacing masthead/stern lights with an all-round light) is addressed by specific rules (e.g., for vessels under 12 meters or those limited in maneuverability), but it is not the required action solely when a vessel cannot meet the masthead light *spacing* requirement. The primary mandate in this specific impracticability scenario is to comply as closely as possible. **D) The vessel must carry only the lights that comply with the rules; the others may be omitted.** This is incorrect and dangerous. Omission of required navigation lights compromises safety and violates the fundamental principle that a vessel must display lights that indicate its status and heading. The rule requires maximum possible compliance, not omission of required lights.