Question 7

The Correct Answer is C **Explanation for Option C (Correct):** Option C states, "You may sound at least five short and rapid blasts on the whistle." This action is governed by **Rule 34(d) (Maneuvering and Warning Signals)**, which applies universally to the COLREGs (International Regulations for Preventing Collisions at Sea). When a vessel is in doubt as to the intentions or actions of the other vessel, or if it perceives that insufficient action is being taken to avoid collision, the vessel may indicate this doubt immediately by sounding at least five short and rapid blasts on the whistle. Although the question references Rule 9 (Narrow Channels), the general rule for signaling doubt (Rule 34(d)) is the appropriate action to take when the operator is "in doubt as to his intentions." **Explanation for Incorrect Options:** **A) You must sound one prolonged and two short blasts:** This signal is used under Rule 35 (Sound Signals in Restricted Visibility) by a power-driven vessel underway but stopped and making no way through the water. It is not the required signal for indicating doubt in clear visibility, nor is it related to Rule 9 (Narrow Channels) passing/overtaking procedures. **B) You should sound one short blast to indicate that you are holding course and speed:** While one short blast signals a maneuver (such as "I intend to alter my course to starboard"), the COLREGs do **not** use sound signals to indicate merely "holding course and speed." Furthermore, if you are in doubt about the other vessel's intentions, sounding a signal indicating a maneuver (one short blast) is inappropriate and potentially misleading. The correct action is to signal doubt using five short blasts. **D) You are required to back down:** Backing down (reversing engines) is an action to avoid collision (Rule 8), not a required sound signal or the initial action when merely "in doubt." While you must take action to avoid collision if necessary, the immediate requirement when in *doubt* is to signal that doubt (Rule 34(d)), which may then be followed by maneuvering action (like slowing or reversing engines) if the situation demands it.