Question 20 ONC03 - Master LT 500-1600 GRT

The Correct Answer is D **Explanation for Option D (Correct Answer):** Option D, "not impede the passage of vessel 'B'," is the correct action because it directly addresses the situation governed by Rule 9 (Narrow Channels) of both the International Regulations for Preventing Collisions at Sea (COLREGs) and the Inland Rules. 1. **Rule 9(b) (Narrow Channels):** This rule specifies that vessels less than 20 meters in length, sailing vessels, or vessels **engaged in fishing** (like Vessel "A") shall not impede the passage of a vessel that can safely navigate only within a narrow channel or fairway (like the large tanker Vessel "B"). 2. **Vessel B's Signal:** Vessel "B" sounds five short and rapid blasts, which is the danger or doubt signal (Rule 34(d)). In this context, Vessel "B" is signaling that Vessel "A" is creating a dangerous situation by potentially impeding its passage or not acting as expected. 3. **Required Action:** Vessel "A," being the fishing vessel, has the obligation under Rule 9 to ensure that Vessel "B" has a safe passage. Therefore, Vessel "A" must take immediate action to move clear and "not impede the passage" of the tanker. **Explanation of Incorrect Options:** * **A) maintain course and speed:** This action is explicitly contrary to Rule 9(b) and the warning given by Vessel "B." Maintaining course and speed would continue to impede the passage of the constrained vessel, risking a collision. * **B) not answer the whistle signals from vessel "B":** While the five-blast signal often does not require an audible reply, ignoring the signal and failing to take corrective maneuvering action is dangerous and violates the obligation to not impede the passage. The intent of the signal is to demand a change in behavior/action. * **C) sound one prolonged followed by two short blasts:** This signal (Rule 35(c) or 34(c), depending on Inland/International) is the required signal for a vessel engaged in fishing that is making way through the water. While required periodically in fog/restricted visibility, it is not the appropriate response to the five-blast danger signal, nor is it the maneuver required to clear the channel for the tanker. The required action is a maneuver (not impeding passage), not a status signal.