Question 6 ONC04 - Mate of LT 500-1600 GRT

The Correct Answer is A **Explanation of A (Sound two prolonged followed by two short blasts):** This scenario is governed by the International Regulations for Preventing Collisions at Sea (COLREGs), specifically Rule 9 (Narrow Channels) and Rule 34 (Manoeuvring and Warning Signals). 1. **The Context:** Overtaking a vessel in a narrow channel when the vessel being overtaken *must* take action to permit safe passing falls under Rule 9(e)(i). 2. **The Signal:** Rule 9(e)(i) mandates that the overtaking vessel (the vessel initiating the manoeuvre) must indicate her intention by sounding the appropriate signal prescribed in Rule 34(c)(i). 3. **Rule 34(c)(i):** This rule specifies the signal for requesting permission to overtake on the **port side** of the vessel ahead. The signal is: **two prolonged blasts followed by two short blasts** (— — • •). This signal means: "I intend to overtake you on your port side." Therefore, sounding two prolonged blasts followed by two short blasts is the required signal when intending to overtake on the port side in a narrow channel where the vessel ahead needs to cooperate. **Explanation of why other options are incorrect:** * **B) Sound two prolonged blasts on the whistle:** This signal (— —) is not a prescribed signal under Rule 34 for indicating an overtaking intention. Prolonged blasts are generally used as warning signals in restricted visibility or when approaching a bend (Rule 35, Rule 34(e)). * **C) No signal is necessary:** This is incorrect. Rule 9(e)(i) explicitly requires the overtaking vessel to sound the prescribed signal before initiating the manoeuvre when the cooperation of the vessel ahead is necessary for safe passage. Navigation in narrow channels requires strict adherence to signalling conventions. * **D) Sound two short blasts:** This signal (• •) means "I am altering my course to port." While it involves a port course change, it is not the internationally mandated signal for requesting permission to overtake on the port side in a narrow channel. The specific narrow channel overtaking request requires the combination of two prolonged and two short blasts (— — • •).