Question 36 ONC01 - Master/Chief Mate Unlimited Tonnage

The Correct Answer is A. **Explanation for Option A (Correct Answer):** The scenario takes place in a narrow channel under the COLREGs (International Regulations for Preventing Collisions at Sea, or Inland Rules which mirror these signals in this context, specifically Rule 9 and Annex III). The overtaking vessel initiates the maneuver by sounding the appropriate signal (e.g., one prolonged blast followed by one short blast under the Inland Rules for passing on the starboard side, or two short blasts under International Rules if visibility allows). Regardless of the initial overtaking intent signal, when the overtaken vessel agrees to the maneuver and determines it is safe to proceed, the required signal of agreement is **one short blast**. This signal indicates "I agree; you may proceed with the passing maneuver." (See Inland Rule 34(c) and (d)). **Explanation for Other Options (Incorrect):** * **B) one prolonged, one short, one prolonged, and one short blast in that order:** This sequence is the **Danger/Doubt** signal (Rule 34(d)). It is used when the overtaken vessel is uncertain of the overtaking vessel's intention, or doubts the maneuver can be safely completed. It is an expression of disagreement or caution, not agreement. * **C) two prolonged blasts:** A prolonged blast is a signal used for leaving a dock or blind bend, or as the maneuvering signal when visibility is restricted. Two prolonged blasts in succession are not the prescribed signal for agreeing to be overtaken. * **D) two prolonged followed by two short blasts:** This sequence is the signal prescribed in the **Inland Rules** for an overtaking vessel intending to pass the vessel ahead on the **port** side (two prolonged followed by two short blasts). It is an initiating signal used by the overtaking vessel, not an answering signal of agreement from the vessel being overtaken.