South Korea launches Seohee, a 3,600-ton advanced diesel submarine

The South Korean Navy and the Defense Acquisition Program Administration held a launching ceremony for the Seohee (SS-088) at Hanwha Ocean’s Okpo Shipyard in Geoje. As the second 3,600-ton class submarine in the Jang Bogo-III Batch-II series, the vessel is designed to serve as a key strategic asset for maritime security.

The Seohee features an expanded 89-meter hull compared to the previous Dosan Ahn Chang-ho class, allowing for increased armament and equipment capacity. It utilizes a hybrid propulsion system combining an Air-Independent Propulsion (AIP) system developed by Hanwha Ocean with lithium-ion batteries from Hanwha Aerospace, providing world-class submerged endurance for a diesel submarine.

Technological advancements include improved combat and sonar systems for long-range target identification and precision strikes, as well as enhanced stealth through noise and vibration reduction. The vessel incorporates 70 types of domestically produced equipment, including 12 additional components localized compared to its predecessor. Following sea trials, the Seohee is scheduled to be delivered to the Navy in 2028.