Question 15

The Correct Answer is A. **Explanation for Option A (4 hours on watch followed by 8 hours rest) being correct:** In a traditional three-person watch rotation (often referred to as a "three-watch system") intended for continuous, 24-hour manning, the total daily hours must be distributed evenly among the three officers (or engineers). * A 24-hour day divided by 3 people means each person is responsible for 8 hours of duty/watch time within a 24-hour cycle. * To achieve the 8 hours of duty and maximize recovery time while maintaining continuous coverage, the structure is typically two 4-hour watches separated by a long rest period. * The rotation is set up as: **4 hours on watch** (e.g., 0000–0400), followed by **8 hours of rest/off-duty**, followed by another **4 hours on watch** (e.g., 1200–1600), followed by the primary **8 hours of rest/sleep** before the next 24-hour cycle begins. * This pattern ensures that each watchkeeper gets 8 hours of rest for every 4 hours of duty, facilitating compliance with maritime fatigue management regulations (such as STCW, which mandates minimum rest periods). **Explanation of why other options are incorrect:** * **B) 6 hours on watch followed by 6 hours rest:** This rotation requires the watchkeeper to perform two 6-hour watches per day, totaling 12 hours of duty. In a three-person rotation, the total hours of duty per person should be 8 hours (24 / 3 = 8). A 12-hour duty day is excessive and unsustainable under standard maritime agreements for continuous manning. * **C) 8 hours on watch followed by 4 hours rest:** This requires 16 hours of duty per person per day (two 8-hour watches), leaving only 8 hours for rest. This is highly unsustainable, violates international rest hour mandates (STCW), and is structurally impossible for a three-person rotation covering only 24 hours of duty (24 / 3 = 8 hours per person). * **D) 8 hours on watch followed by 8 hours rest:** This structure would require 24 hours of duty per person (three 8-hour watches) over a 24-hour period, leaving no dedicated rest time. It also cannot work in a three-person rotation where the total available duty hours are 24. This model is fundamentally flawed for continuous watchkeeping.