Mayang Do Naval Base
Mayang Do is one of two North Korean submarine bases. It provides operation and logistical support for submarines, antisubmarine craft, and patrol craft.
The base is located in a natural harbor on the east coast, approx. 30 miles NE of Hamhung. The harbor is located on the north side of Mayang-do, an island that lies 1 mile of the mainland south of Sinp'o. The facilities are located in two bays with central depths of 48-59 feet, separated by a peninsula. There are two approaches: the western channel is 1/2 mile wide with a controlling depth of 30 ft.; the eastern channel is 1 mile wide with a controlling depth of 52 feet. Tides and currents are negligible, and ice does not interrupt navigation.
Anchorage in the strait provides many free-swinging berths over a mud and sand bottom, with depths of 20-60 ft. Berthing facilities alongside are provided by 1830 ft. of principal wharfage at 4 quays and one pier. Depths alongside range from 10 to 21 feet. A POL pier and supplemental wharfage for small craft are also present. There is extensive warehouse and POL storage present.
The shipyard is reported to have a 360 x 70 foot graving dock, a 270 foot marine railway, and other facilities for repair of sumbarines and patrol craft. Intelligence from the 1970s reported that the installation was being expanded with additional wharfage, storage, barracks, and shipyard facilities.
