In light of Pudge's reported visit to Naval Unit 189:A review of commercial satellite imagery from 2010 until the present has revealed the presence of a previously unidentified submarine moored in the secured boat basin at the Sinpo South Shipyard. This shipyard, also known by the cover designation “Pongdae Boiler Plant,” is the primary manufacturing facility for North Korea’s submarines and the headquarters of the Maritime Research Institute of the Academy of the National Defense Science. The institute is responsible for research and development of maritime technology, naval vessels and submarines, and naval related armaments and missiles.
The newly identified submarine has a length of approximately 67 meters and a beam of 6.6 meters, possesses a rounded bow, a conning tower located amidships, and no visible diving planes. These dimensions suggest a dive displacement in the 900-1,500 ton range. Visible in the image are mooring lines, people moving about and equipment stored on the pier adjacent to the submarine. The long object on the pier forward of the conning tower is likely a line of closely packed shipping crates or equipment and not a missile tube. A blue tarp is covering the stern portion of the top of the sail. No torpedo or missile tubes are readily discernible on the bow or deck of the submarine in any of the available imagery.
While the boat bears a superficial resemblance to the Russian KILO or LADA class patrol submarines, it lacks the teardrop hull-shape of the former and the conning tower mounted diving planes of the latter. Additional research shows, however, a close resemblance in size and shape to the former Yugoslavian SAVA and HEROJ class submarines. A Yugoslavian origin for the design would not be unusual since the North Koreans acquired a number of submarine designs from that nation during the 1970s and used them as the basis for several experimental designs as well as the yugo class of midget submarines.