South Korea's Stealthy Secret Weapon: Unveiling the Covert 3,000-ton Submarine

The Republic of Korea Navy (ROK Navy) added a new 3,000-tonne submarine with enhanced capabilities to perform covert underwater missions and precision strikes.

Submarine ROCKS Ahn Mu

The ROKS Ahn Mu, named after a Korean independence fighter, was delivered on April 20 at Daewoo Shipbuilding and Marine Engineering Co.’s Okpo shipyard in Geoje. Following eight months of operational testing, she is scheduled to enter service next year.

This submarine is the second built under the Changbogo-III Batch-I program, designed to produce three 3,000-ton, 83-meter-long submarines with a capacity for 50 crew members.

The Dosan Ahn Chang-ho class integrates the Korean Vertical Launch System, which can carry up to ten “Chonryong” cruise missiles and “Hyunmoo” submarine-launched ballistic missiles (SLBM).

South Korea's Stealthy Secret Weapon: Unveiling the Covert 3



covert missions

The ROKS Ahn Mu is a crucial element of South Korea’s Kill Chain preemptive strike system, part of its triple defense architecture. It is equipped with vertical launch tubes for submarine-launched ballistic missiles, allowing it to perform precision strikes against key ground targets in “strategic” contingency missions.

In addition, it features advanced noise and vibration reduction technologies, state-of-the-art sonar and combat systems, and numerous improvements over its predecessors.

With a displacement of more than 3,800 tons submerged during sea trials, they are the largest conventional submarines ever built by South Korea.

Korean Attack Submarine Program

The Dosan Ahn Changho-class (KSS-III) submarines are part of the Korean Attack Submarine Program, a three-phase initiative to build 27 attack submarines for the ROKN between 1994 and 2029.

The KSS-III phase consists of developing nine diesel-electric submarines capable of firing submarine-launched ballistic missiles (SLBMs), built in three batches between 2014 and 2029.

The Republic of Korea (South Korea) has launched the Korean Attack Submarine Program (KASP) to improve its navy and guarantee maritime security. South Korea’s submarine fleet will be strengthened, and its deterrent posture maintained thanks to the KASP’s focus on homegrown technology and cutting-edge research.

The need to defend against prospective threats from North Korea and other maritime foes prompted the creation of the KASP. The program is motivated by the need for a modern, versatile submarine fleet that can gather intelligence, conduct reconnaissance, and launch offensive operations if necessary.

The KASP emphasizes domestic submarine manufacturing. The KASP hopes to use South Korea’s progress in its shipbuilding industry to its advantage by building cutting-edge submarines there. The country’s defense industry benefits from this strategy, creating highly trained employees.

The KASP includes the planning, research, and building of a new class of assault submarines, the KSS-III. These subs will have cutting-edge features, including increased stealth, longer range, and more powerful weapons. 

Submarines equipped with cutting-edge technology, such as air-independent propulsion, improved sonar systems, and powerful weapons systems, will have a distinct tactical advantage.

The KASP also emphasizes the value of working together across borders. South Korea has been actively pursuing partnerships with international defense firms and specialists so that it may learn from their experiences and knowledge. 

South Korea hopes to significantly advance the capabilities of the KASP by incorporating cutting-edge technologies and best practices through partnerships with countries like Germany and France.

South Korea is serious about its defense, as evidenced by the Korean Attack Submarine Program’s massive investment in its naval might. The Republic of Korea (South Korea) plans to guarantee maritime security, shield national interests, and contribute to regional stability by pursuing indigenous development, incorporating cutting-edge technologies, and encouraging international collaborations. 

When fully operational, the KASP will cement South Korea’s position as a technologically advanced naval power in the Indo-Pacific area and make it a major player in submarine warfare.


The Republic of Korean Navy acquired a 3,000-ton submarine with enhanced covert missions and precision strikes capabilities. The ROKS Ahn Mu is part of the Changbogo-III Lot-I program and is an essential component of South Korea’s Kill Chain pre-emptive strike system.