Every vessel shall proceed in accordance with the LAW FOR PREVENTING COLLISION AT SEA around the Japanese sea area so that may avoid a collision. It is very important that the application of Navigation Rule should be proper. The application of Navigation Rule begins when the Risk of the collision is decided rationally. As for the vessel which has keep out of the way another vessel at first, the duty doesn't change due to the change in the conditions after that caused by the progress of the time. But, it came to appear that it lets think over about the judgment of the application of Marine Accidents Inquiry recently. So, the following result could get it when the judgment record of Marine Accidents Inquiry Agency (MAIA) was researched. The judgment of the application of Navigation Rule varies even in the same circumstances among navigators. And, their good seamanship is missing with neglecting an ordinary practice of seamen. The authors consider that it is necessary that the judgment of the application of Navigation Rule becomes the same in not only navigators but also all persons concerned to reduce a collision. As for proposing it as a conclusion from this research, it is necessary it unifies the recognition of every seafarer, and try to reconsider education in the first once again. Then, educational facilities and MAIA should keep in touch with seafarers for more improvement.
