Eight thousand two hundred tons of Aegis destroyer went into the water at Ulsan, South Korea, on Sept. 30, 2026, when HD Hyundai Heavy Industries launched the future ROKS Daeho Kim Jong-seo. She is the third and final ship of the Republic of Korea Navy’s KDX-III Batch-II program, and the last of the six Aegis destroyers South Korea set out to build.
The ship still has sea trials ahead of her. Once she is delivered in December 2027, the Republic of Korea Navy will operate six Aegis-equipped destroyers, three from each batch of the KDX-III program.
HD Hyundai Heavy Industries announced the launching ceremony, and Naval News reported on Oct. 1 that the ship is “the Republic of Korean (ROK) Navy’s third and final next-generation Aegis destroyer (KDX-III Batch-II program), completing South Korea’s six-ship Aegis fleet.” According to the same report, roughly 350 government, military and company officials attended the ceremony at the Ulsan yard; South Korea’s president was among them.
Daeho Kim Jong-seo by the numbers
Naval News, citing the builder, gives the destroyer a length of 170 meters and a light displacement of about 8,200 tons. Baird Maritime, reporting Sept. 30, adds a beam of 21 meters and a top speed of 30 knots, “courtesy of four gas turbines and two hybrid electric propulsion units.”
Both reports describe an integrated sonar suite developed in South Korea and a ballistic missile system. Naval News says that combination gives the Batch-II ships interception capabilities the earlier Sejong the Great-class destroyers do not have. Baird Maritime notes the sonar fit includes both hull-mounted and towed arrays.
The name joins the pen name and given name of a general. Per Naval News, the ship honors General Kim Jong-seo, “who led the expansion of Korea’s northern frontier during the early Joseon period.”
Three Jeongjo the Great-class ships in four years
The lead ship, ROKS Jeongjo the Great, was launched on July 28, 2022, and delivered to the Navy on Nov. 27, 2024, according to Naval News. That report says she passed about 550 evaluations before handover and was built under a 2019 contract with South Korea’s Defense Acquisition Program Administration.
The same 2024 report put the jump in size between batches in plain terms: the Batch-II ships displace 8,200 tons, up from 7,600 tons for Batch-I. It described a combat system that pairs the U.S.-built Aegis with Korean-developed equipment, including the KVLS-II vertical launcher, long-range surface-to-air missiles and ballistic missile interceptors, and noted that the ships operate MH-60R Seahawk helicopters.
HD HHI launched ROKS Dasan Jeong Yak-yong on Sept. 17, 2025, with delivery then planned for 2026, Naval News reported at the time. That report put the class’s full-load displacement at more than 10,000 tons, against the 8,200-ton light figure the builder uses.
Six Aegis destroyers, five from one yard
When Daeho Kim Jong-seo enters service, the Navy’s Aegis force will stand at three Sejong the Great-class ships of KDX-III Batch-I and three Jeongjo the Great-class ships of Batch-II. HD Hyundai Heavy Industries designed and built five of the six, including all three Batch-II hulls, per the Oct. 1 Naval News report.
The interceptor capability is what separates the second trio from the first. Naval News’ launch report singles it out as the capability the earlier Sejong the Great-class destroyers lack, alongside the domestically developed sonar suite.
The next step for Daeho Kim Jong-seo is fitting out and sea trials at Ulsan, followed by delivery to the Republic of Korea Navy in December 2027.
Top image: ROKS Jeongjo the Great (DDG 995), the first KDX-III Batch-II destroyer and a sister ship of Daeho Kim Jong-seo, departs Pearl Harbor for RIMPAC 2026. Image Credit: U.S. Navy photo by Mass Communication Specialist 1st Class Vance Hand — Public domain / Wikimedia Commons
This article was produced with the assistance of AI and reviewed by Combat Rated editors prior to publication.