Question 13 OSV01 - Master/Chief Mate - Offshore Supply Vessels

The Correct Answer is A. **Explanation for Option A (Correct)** Option A states: "Slow to minimum to maintain course and navigate with caution." This action is required under Rule 19 (Conduct of Vessels in Restricted Visibility), which applies to both International and Inland Waters. Specifically, Rule 19(e) mandates that if a vessel hears the fog signal of another vessel apparently forward of the beam (ahead) or if close quarters cannot be avoided, the vessel must reduce her speed to the minimum at which she can be kept on her course. If necessary, the vessel must take all way off. Navigating with caution is a fundamental requirement in restricted visibility (Rule 19(b)). **Explanation for Other Options (Incorrect)** * **B) Slow to moderate speed and navigate with caution:** Rule 19 requires speed to be reduced to the *minimum* necessary to maintain course, not merely a moderate speed. A "moderate speed" is too fast when the location of an approaching vessel ahead is unknown in heavy fog. * **C) Stop engines and navigate with caution:** While stopping engines may sometimes be required (e.g., if "all way off" is necessary), Rule 19(e) primarily requires reducing speed to the minimum to *maintain course*. Stopping engines completely might lead to the vessel losing steerageway, which could make maneuvering more difficult and less predictable. This action is not the primary mandatory requirement under 19(e). * **D) Maintain speed and sound five short and rapid blasts:** Maintaining speed is a direct violation of Rule 19(e), which requires slowing down. Sounding five short and rapid blasts (the danger signal) is used to indicate doubt about another vessel's intentions or whether sufficient action is being taken to avoid collision (Rule 34(d)). It is not the required signal simply upon hearing a vessel ahead in fog; the required action is changing speed/course, and the appropriate signal would be the mandatory fog signal (Rule 35).