Question 50 RVR04 - Master or Mate of LT 200 GRT

The Correct Answer is D. **Why Option D ("a vessel engaged in diving operations") is correct:** The signal specified—a vessel exhibiting a rigid replica of the International Code flag "A" (Alpha)—is the internationally recognized signal required by the **International Regulations for Preventing Collisions at Sea (COLREGs)**, Rule 27(e). This rule states that a vessel engaged in diving operations that is restricted in its ability to maneuver shall exhibit, by day, a rigid replica of the International Code flag "A". The Code flag "A" itself is white and blue, shaped like a swallowtail, and it means: "I am restricted in my ability to maneuver; keep clear at slow speed." This requirement applies to both international (high seas) and inland waters that adhere to COLREGs or compatible regulations (such as the US Inland Rules, which often incorporate COLREGs signals). **Why the other options are incorrect:** * **A) a vessel transferring explosives:** While a vessel transferring dangerous cargo (including explosives) must take special precautions and might use specific port/local signals, the primary COLREGs signal for general vessel status (like restricted maneuverability) is not mandated to be the rigid "Alpha" flag simply for carrying or transferring explosives. * **B) a vessel engaged in underway replenishment:** Underway replenishment (a naval operation where one vessel transfers fuel/supplies to another) falls under the category of a vessel **restricted in its ability to maneuver** (COLREGs Rule 3(g)). Such a vessel must display the lights/shapes for a "vessel restricted in its ability to maneuver" (ball-diamond-ball shape by day), but it is not specifically mandated to exhibit the rigid "Alpha" flag; that flag is reserved specifically for diving operations under Rule 27(e). * **C) a vessel pulling a submarine cable:** A vessel engaged in operations such as laying, servicing, or picking up a submarine cable is also classified as a vessel **restricted in its ability to maneuver** (COLREGs Rule 3(g)). Like the vessel engaged in replenishment (Option B), it must display the ball-diamond-ball shapes (or corresponding lights) but is not required to display the rigid "Alpha" flag, which is dedicated to divers.