Question 485 Rules of the Road

The correct answer is D) Four short blasts. According to the International Regulations for Preventing Collisions at Sea (COLREGS), the signal of four short blasts on the whistle is the maneuver signal that may be sounded only by vessels in restricted visibility. This signal indicates that the vessel is maneuvering to avoid a collision. The other answer choices are incorrect because they do not represent the proper signal for vessels in restricted visibility. Options A, B, and C describe different whistle signals used for other purposes, such as warning signals or maneuvering signals in clear visibility.