Abstract
The rule 19 of INTERNATIONAL REGULATIONS FOR PREVENTING COLLISIONS AT SEA, 1972 provides for conduct of vessels in restricted visibility. The rule 19 demands that a vessel which detects by radar alone the presence of another vessel shall determine if a close-quarters situation is developing and/or risk of collision exists. If so, the vessel shall take avoiding action in ample time. And the vessel cannot avoid a close-quarters situation with another vessel forward of her beam, shall reduce her speed to minimum at which she can be kept on her course, and if necessary take all her way off. But it is difficult to decide the determination point concisely on the service realities. The Marine Accidents Inquiry Agencies judgment record was investigating analyzed to clarify the determination point from navigator's standpoint, therefore the following result was obtained. The determination point of "a Close-quarters Situation is developing in restricted visibility" is that 2.5 nautical miles (relative distance with another vessel) forward of vessel beam and 1.5 nautical miles (relative distance with another vessel) backward of vessel beam
