Question 7 ONC02 - Second Mate/Third Mate Unlimited Tonnage

The Correct Answer is C **Explanation for C (Correct Answer):** Option C states, "You may sound at least five short and rapid blasts on the whistle." This action is governed by **Rule 34 (Maneuvering and Warning Signals)**, which is closely related to situations encountered under **Rule 9 (Narrow Channels)** and **Rule 19 (Restricted Visibility)**, although Rule 9 is specifically mentioned in the prompt. When a vessel is in doubt as to the intention or action of another vessel, or believes a close-quarters situation is developing, Rule 34(d) (International Regulations for Preventing Collision at Sea – COLREGs) permits the use of the danger signal. The danger signal consists of **at least five short and rapid blasts** on the whistle, indicating doubt or disagreement with the other vessel's actions, and requiring clarification or caution. Since the scenario involves operating in a narrow channel (Rule 9) where safe maneuverability is limited and the operator is "in doubt as to his intentions," sounding the danger signal is the appropriate action allowed by the rules. **Explanation for Incorrect Options:** **A) You must sound one prolonged and two short blasts:** This signal (Rule 35(c)) is used *only* when a vessel is navigating in or near an area of restricted visibility (fog signal) and is a power-driven vessel underway but stopped and not making way through the water. It is not the signal used for indicating doubt in clear visibility in a narrow channel. **B) You should sound one short blast to indicate that you are holding course and speed:** In International Rules (COLREGs), a single short blast (Rule 34(a)) means "I am altering my course to starboard." Sounding one short blast when holding course and speed would be misleading and a violation of the Rules. Furthermore, when in doubt, the operator should sound the danger signal (five blasts), not a course-alteration signal. **D) You are required to back down:** While backing down (reversing engines) might be necessary later as an action to avoid collision (Rule 8), the immediate action when in doubt about intentions is to signal that doubt using the required whistle signals (Rule 34(d)). The rules do not *require* immediate backing down solely based on doubt; the requirement is to signal the danger/doubt first.