3,600-ton-class Submarine 'Seo Hui' Launched

Second Jang Bogo-III Batch-II Submarine... Larger Hull and Increased Weapons-Carrying Capacity

The Seohee, the second 3,600-ton-class submarine, will be launched in a ceremony on November 3 at Hanwha Ocean's Okpo Shipyard in Geoje. Following the Jang Yeong-sil, launched in October 2025, the Seohee is the second Jangbogo-III Batch-II (Jang Yeong-sil-class) submarine to be launched.

On November 3, the Navy said, "The Seohee is a world-class diesel-powered submarine and a key strategic asset capable of deterring maritime security threats around the Korean Peninsula and maintaining a firm strategic posture for responding to contingencies."

Compared with Batch-I (Dosan Ahn Changho-class, 3,000-ton-class) submarines, the Seohee has enhanced detection and strike capabilities, stealth, and survivability. Its hull is larger, measuring 89 meters in length, expanding its capacity to carry weapons and equipment. Improvements to its combat system, the submarine's brain, and sonar system, its eyes and ears, have also strengthened its ability to identify multiple targets at long range and strike them precisely.

Yonhap News Agency

Equipped with a domestically developed lithium battery system whose reliability has been verified, the submarine can remain submerged longer and travel at maximum speed for longer periods, significantly enhancing its operational capabilities. It also features advanced noise-reduction technology for a high degree of stealth. In addition, an auxiliary propulsion system enables the submarine to maneuver even if its main propulsion system fails in an emergency, improving its survivability.

It has also domestically produced 12 additional types of equipment compared with the Dosan Ahn Changho class, bringing the total to 70 types of domestically produced equipment. This helps ensure stable follow-on logistics support and strengthens the export competitiveness of K-submarines.

The submarine is named after Seo Hui, a prominent Goryeo-era statesman who secured the Gangdong Six Prefectures without bloodshed through an outstanding diplomatic negotiation during the Khitan invasion. The Navy said Seo Hui's military and diplomatic achievements, as well as his spirit of overcoming national crises, make the name fitting for a key maritime defense asset. The Seohee will undergo sea trials before being delivered to the Navy in 2028. It is scheduled to enter operational service after completing the commissioning process.

This content was produced with the assistance of AI translation services.