sentences:  The headquarters for the force was based in the North Korean city of Wonsan, and was operational by July 1946.The headquarters were then expanded and moved to the capital, Pyongyang, for more effective management of seabound traffic, and the forces were renamed Marine Patrols in December of the same year.The Marine Patrol Academy was established in Wonsan in June 1947 in order to train and commission a professional corps of naval officers.