Question 50 RVR01 - Master of Unlimited Tonnage

The Correct Answer is D ### Explanation of Correct Option (D) **D) a vessel engaged in diving operations** is correct because both the International Regulations for Preventing Collisions at Sea (COLREGs) and the U.S. Inland Rules require a vessel engaged in diving operations (a vessel Restricted in its Ability to Maneuver, or RAM) to display a rigid replica of the International Code flag "A" (Alpha flag). The Alpha flag, when used in this context, serves as a specialized daylight signal indicating: **"I am a vessel engaged in diving operations; keep well clear at slow speed."** This signal is used in addition to, or in place of, the standard RAM signals (ball-diamond-ball) during daylight hours, depending on the rules applicable and the size of the vessel. ### Explanation of Incorrect Options **A) a vessel transferring explosives** This vessel is generally required to display the International Code flag "B" (Bravo flag), which means "I am taking on, discharging, or carrying dangerous goods." It does not use the Alpha flag. **B) a vessel engaged in underway replenishment** This vessel is classified as a vessel Restricted in its Ability to Maneuver (RAM). It must display the standard RAM signals: three shapes (ball-diamond-ball) or three all-round lights (red-white-red) vertically. It does not use the specialized Alpha flag. **C) a vessel pulling a submarine cable** A vessel engaged in laying, servicing, or picking up a submarine cable or pipeline is also a vessel Restricted in its Ability to Maneuver (RAM). It must display the standard RAM signals (ball-diamond-ball or red-white-red lights). The specific use of the Alpha flag is reserved exclusively for diving operations.