Question 50 RVR03 - Mate of LT 500-1600 GRT

The Correct Answer is D 1. **Why option D ("a vessel engaged in diving operations") is correct:** The vessel engaged in diving operations is required under both the International Regulations for Preventing Collisions at Sea (COLREGs) Rule 27(e) and the Inland Rules (33 CFR § 83.27(e)) to display the signal indicating that it is restricted in its ability to maneuver and that divers are down. This signal is specified as: * **Daytime:** Three shapes in a vertical line: ball, diamond, ball. * **Nighttime:** Three all-round lights in a vertical line: red, white, red. * **Additional Signal (Mandatory for both International and Inland):** The vessel must also exhibit a rigid replica of the International Code flag "A" (Alpha flag) not less than one meter in height. The Alpha flag means: "I have a diver down; keep well clear at slow speed." 2. **Why the other options are incorrect:** * **A) a vessel transferring explosives:** While a vessel transferring dangerous cargo, including explosives, may exhibit signals related to dangerous goods, there is no requirement in COLREGs or Inland Rules to display the rigid replica of the International Code flag "A" specifically for this operation. This vessel would typically be governed by signals related to vessels constrained by draft or restricted in ability to maneuver, but not the diver signal. * **B) a vessel engaged in underway replenishment:** A vessel engaged in underway replenishment is a vessel restricted in its ability to maneuver and would display the ball-diamond-ball shapes (or R-W-R lights) under Rule 27(b). However, the specific requirement to display the rigid replica of the International Code flag "A" is uniquely tied to diving operations (Rule 27(e)), not general replenishment or transfer operations. * **C) a vessel pulling a submarine cable:** A vessel engaged in laying, servicing, or picking up a cable (or pipeline) is also a vessel restricted in its ability to maneuver (Rule 27(c)). It exhibits the shapes/lights corresponding to its specific operation (e.g., two balls in a vertical line if making way, two diamonds if at anchor). It is not required to display the International Code flag "A", as this operation does not involve a diver being in the water requiring the specific diver warning signal.