Question 7 ONC04 - Mate of LT 500-1600 GRT

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(d) of the International Regulations for Preventing Collisions at Sea (COLREGs), which applies universally (not just to narrow channels) when doubt exists. However, Rule 9 (Narrow Channels) itself, while focused on movement within the channel, does not override the fundamental collision avoidance provisions regarding doubt and signals. When a vessel is in doubt as to the intentions or actions of another vessel, the proper signal to indicate this doubt (the "danger signal") is at least five short and rapid blasts on the whistle. This signal alerts the other vessel that the operator perceives a dangerous situation or is uncertain of the maneuvering required, which is highly relevant in a potential crossing situation in a narrow channel where maneuvering room is limited and doubt has arisen. **Explanation of Incorrect Options:** **A) You must sound one prolonged and two short blasts:** This signal (Rule 35) is the required signal for a power-driven vessel **underway but stopped** (making no way through the water) in restricted visibility, which is not the scenario described. Furthermore, sounding one prolonged and two short blasts is used in restricted visibility (Rule 35), not typically in clear visibility to express doubt or indicate intention in a crossing situation (Rule 34). **B) You should sound one short blast to indicate that you are holding course and speed:** One short blast (Rule 34(a)(i)) means "I am altering my course to starboard." This is a maneuvering signal indicating a change in direction, not a signal of doubt, nor is it used to communicate that you are holding course and speed. (Under International Rules, signals are only required when maneuvering, not merely for holding course and speed, unless specified by specific local rules or the Inland Rules counterpart.) **D) You are required to back down:** While taking early and substantial action is required (Rule 8), the specific maneuver (like backing down) is only mandatory if it is the best action to avoid collision. The initial step when in doubt is to communicate the doubt using the prescribed sound signal (five short blasts). There is no requirement in Rule 9 or Rule 34 to immediately back down merely because doubt exists; immediate action may involve slowing, stopping, or sounding the danger signal first.