
Sharp Focus: A Unique View of the Mayang-do Submarine Base
Key Findings
- The Mayang-do Navy Shipyard and submarine bases are the largest facilities of their kind in North Korea. As such, they play a crucial role in the operational status, repair, and maintenance of the nation’s submarine force.
- Using unique off-nadir imagery collection, this report provides a close-up focus of these facilities, including views of the ROMEO class and SANGO class submarines, and Kim Jong-un’s yacht.
- This is the second of several reports providing a unique view of the Sinpo South Shipyard, Sinpo area, and Mayang-do navy facilities using a remarkable high off-nadir (HON) image collected by Maxar Technologies during April 2021.
As with our recent Sharp Focus high off-nadir (HON) report of the Sinpo South Shipyard, the same April 21, 2021 Maxar Technologies image provides a unique look at the Mayang-do submarine bases and navy shipyard. While a majority of satellite imagery is collected at 0O to 35O off-nadir, the April 21 image was collected at 49.6O off-nadir—placing the Worldview 2 satellite approximately 780 kilometers away over the Yellow Sea. This image presents a view that an individual would have if they were looking at the facility out the window of an airliner showing the sides of buildings and objects and providing a sense of relative height.

Moving from west to east, the first facility that comes into view is the civilian fishing village located at the base of the westernmost bay. This village consists of a dock, warehouses, housing, and what appears to be a small processing plant.
Moving east, in the next bay are the Mayang-do Navy Shipyard (often mistakenly identified as a submarine base) and the often-overlooked Mayang-do (Pegumi) midget submarine (SSW) base. This shipyard is the largest submarine maintenance and repair facility in North Korea. It consists of a comprehensive collection of docks, warehouses, engineering offices, machine shops, fabrication halls, and support facilities. Most notable among the latter are a large approximately 115-by-25-meter graving dock, inclined repair way, and an abandoned construction/maintenance hall. The graving dock is most frequently seen being occupied by ROMEO class and SANGO class submarines. Submarines and warships are almost always observed alongside the adjacent docks. Just visible is a small “target ship” built on an old hull to be used during a future training cycle as a target for live-fire anti-ship missile exercises.



Located along the northeast shore of the bay is the small, often ignored Mayang-do (Pegumi) midget submarine (SSW) base. Visible in the image are seven midget submarine shelters with a transfer table in front of them and 12 midget (SSW) submarines.
Located in the furthest east within the largest bay on the island are two navy bases: the Mayang-do ROMEO class submarine (SS) base and the joint Mayang-do patrol boat (PC/PB) and SANGO class (SSC) submarine base. The former is the largest submarine base on the east coast and consists of a headquarters and barracks area, pier with four ROMEO class submarines (SS), a yacht used by Kim Jong-un, a dock immediately to the northeast with three additional ROMEO class submarines, inclined repair way, a barracks area, and miscellaneous support facilities. ROMEO class submarines are sometimes seen at a second pier located on the west side of the bay. The dock immediately to the northeast is often observed with four ROMEO class submarines as well as one or two SANGO class submarines present.


Along the northeast shore of the bay is the joint Mayang-do patrol boat (PC/PB) and SANGO class (SSC) submarine base that consists of an extended dock, headquarters, barracks, and housing areas. Five to ten patrol boats and two to five SANGO class submarines are often observed here.