(Yonhap Feature) Inside S. Korea's new submarine: a rare look into naval power, global push

Down a narrow and cramped corridor inside South Korea's new submarine lies an overwhelming array of advanced technology. This 89-meter-long, 3,600-ton Seo Hui attack submarine, the second vessel in the ambitious Jang Bogo-III Batch-II program, stood docked at Hanwha Ocean Co.'s shipyard in Geoje when unveiled to the press. Standing as a testament to South Korea's naval power, the Seo Hui features vertical launch tubes for submarine-launched ballistic missiles, an upgraded sensory suite, and an integrated combat management system.

Equipped with advanced weaponry, the submarine's hybrid propulsion system—combining an air-independent propulsion fuel-cell system with high-capacity lithium-ion batteries—provides unprecedented submerged endurance, allowing it to remain underwater longer than any other diesel-fueled vessel. Its spacious crew quarters and upgraded living conditions mark a significant departure from earlier submarine models.

The Seo Hui is set to launch in November, joining a fleet of advanced vessels designed to counter North Korea's expanding naval capabilities.