Question 20 MODU01 - Offshore Installation Manager

The Correct Answer is D. **Explanation for Option D (Correct):** Option D, "not impede the passage of vessel 'B'", is the correct action because Vessel "A" (engaged in fishing) is operating in a narrow channel. Rule 9(b) of the COLREGs (both International and Inland) explicitly states that a vessel of less than 20 meters in length or a sailing vessel **shall not impede the passage** of a vessel that can safely navigate only within a narrow channel or fairway. Furthermore, Rule 18(d)(i) states that vessels engaged in fishing shall not impede the passage of any other vessel navigating within a narrow channel or fairway. Vessel "B" is a tanker, a large vessel likely restricted to the channel. When Vessel "B" sounds five short and rapid blasts, it is indicating danger or doubt that the proposed action (likely B's intent to proceed) is safe, likely due to Vessel A's presence. In this scenario, Vessel "A" has the duty to avoid impeding the safe passage of the larger, channel-restricted vessel. **Explanation for Other Options (Incorrect):** * **A) maintain course and speed:** This is incorrect. Vessel "B's" five short blasts indicate immediate danger or doubt, demanding that Vessel "A" take immediate evasive action, which means changing course or speed to ensure Vessel "B" can proceed safely. Maintaining course and speed would violate Vessel A's duty not to impede traffic in a narrow channel and ignore the danger signal. * **B) not answer the whistle signals from vessel "B":** This is incorrect. While the five-blast signal is a danger signal (not an operating signal requiring an immediate response like "I agree" or "I disagree"), Vessel "A" must acknowledge the situation by taking immediate action (Rule 2, Good Seamanship) and ensure the safe passage of Vessel "B" (Rule 9). Ignoring the signal and taking no action is unsafe and irresponsible. * **C) sound one prolonged followed by two short blasts:** This signal indicates a vessel is preparing to overtake on the port side in a narrow channel (Inland Rules) or a towing signal (International Rules, not applicable here). It is not the appropriate response to a danger signal, nor does it fulfill Vessel A's duty to clear the channel. Vessel "A" must take action to move out of the way, not propose an overtaking maneuver.