**OVERVIEW:** The Cosmos SX-756/K Class is a diesel-electric powered submarine designed and operated by the Republic of Korea Navy (ROKN).

**DETAILS:**

The Cosmos SX-756/K class represents South Korea's initial foray into indigenous submarine design and construction. Commissioned in 1989, these submarines were developed by Korea Tacoma Marine Industries (now Hanjin Heavy Industries) with technical assistance from Cosmos Submarines of Italy. The design philosophy emphasized coastal defense and special operations capabilities within the challenging littoral environment surrounding the Korean Peninsula. Prior to this, the ROKN relied on foreign-built submarines. The SX-756/K program allowed South Korea to develop critical domestic expertise in submarine construction, maintenance, and operation, paving the way for more advanced submarine programs like the Chang Bogo and Son Won-il classes. The acquisition of this technical knowledge base was paramount to Seoul achieving a level of maritime self-reliance.

The primary roles of the Cosmos SX-756/K class are believed to be focused on coastal patrol, surveillance, and potentially special forces insertion and extraction. Due to their small size and limited endurance, they are not suited for extended blue-water operations or anti-submarine warfare (ASW) patrols far from shore. Their deployment is likely confined to the Yellow Sea, the Korea Strait, and the Sea of Japan (East Sea). The lack of dedicated torpedo or missile armament points to a reliance on stealth and discretion for mission success, rather than direct engagement with enemy surface combatants or submarines. Therefore, any offensive capability would be focused on the clandestine delivery of naval special warfare teams.

The Cosmos SX-756/K class is equipped with a generic submarine periscope that incorporates optical sensors for visual observation and target identification. The periscope is a critical tool for navigation, surveillance, and target acquisition in a submerged environment. Without sonar or electronic warfare support measures, the submarine's situational awareness is primarily limited to visual range, making acoustic stealth and skillful maneuvering paramount for survival in a contested environment. Given the submarine's role in potential covert operations, the optical sensors of the periscope would be vital in positively identifying targets or landing zones prior to action by any embarked special forces units. The submarine's design also likely incorporates features to minimize acoustic signature, such as a low-noise propulsion system and vibration damping measures.

**SPECIFICATION:** Length: 25.2 m || Beam: 2.1 m || Draft: 4.0 m || Disp: 80 t

**SENSORS:** Generic Submarine Periscope, Optical

**ARMAMENT:** None