Dredger "Kaisho-Maru"

"Kaisho-Maru" is the latest drag-suction dredge and oil recovery vessel which has been planned by the 4th District Port and Harbor Construction Bureau, Ministry of Transport and is being constructed at IHI Tokyo Shipyard. Especially this is a world largest class oil recovery vessel. On this vessel, various types of sensors are adopted to support automatic dredging and oil recovery operations. From the standpoint of underwater technology, this vessel is equipped with a seabed mapping system which supports more accurate and efficient dredge operations, called the dredge operation support (DOS) system. The paper presents general features of the vessel and a detailed explanation of the DOS system.