Question 7 MODU01 - Offshore Installation Manager

The Correct Answer is C **Explanation for C being correct:** Option C ("You may sound at least five short and rapid blasts on the whistle") is correct because it addresses a situation of doubt as to the intentions of the crossing vessel. International Regulations for Preventing Collisions at Sea (COLREGs), specifically **Rule 34(d)** (Maneuvering and Warning Signals, which applies generally, including in narrow channels under Rule 9 circumstances), states that when vessels are in sight of one another, if either vessel is in doubt as to the intentions or actions of the other vessel, or is concerned whether sufficient action is being taken by the other to avoid collision, the vessel in doubt **shall** indicate such doubt by sounding at least five short and rapid blasts on the whistle (the danger signal). While the primary situation described relates to Rule 9 (Narrow Channels), the action taken when in doubt is governed by Rule 34(d). **Why the other options are incorrect:** **A) You must sound one prolonged and two short blasts:** This signal (Rule 35(e)) is used by a power-driven vessel when under way but stopped and making no way through the water, or by a vessel towing/pushing in restricted visibility (Rule 35(c)). It is not the signal used to express doubt about another vessel's intentions when in sight. **B) You should sound one short blast to indicate that you are holding course and speed:** Under COLREGs (Rule 34(a)), one short blast means, "I am altering my course to starboard." Sounding one short blast when you intend to hold course and speed is misleading and violates the regulation. Additionally, Rule 9 restricts when sound signals for maneuvering are used in narrow channels, but fundamentally, the signal for doubt is the danger signal, not the maneuvering signal. **D) You are required to back down:** While maneuvering action is required to avoid collision if necessary (Rule 8), there is no specific rule requiring a vessel that is staying within a narrow channel to immediately back down simply because another vessel's intentions are uncertain. The immediate, required action for expressing doubt is sounding the danger signal (five blasts), giving the other vessel a chance to clarify or act before severe maneuvering (like backing down) is mandated.