Both of South Korea's naval intelligence ships were out of service for about 40 days

Both of the South Korean navy's oceanographic information ships, the vessels it uses to gather signals intelligence at sea, were out of action at the same time for roughly 40 days from September into mid-October, according to figures obtained by Han Gi-ho, a People Power Party lawmaker, and reported on Monday 19 October by The Chosun Ilbo.

The two ships are the 2,800-ton Shinsegi, commissioned in 2003, and the 3,500-ton Shingiwon, commissioned in 2012. The Shingiwon went into a scheduled depot-level overhaul, the navy's most extensive maintenance tier, in July. The older Shinsegi then needed repairs of its own because of its age, leaving neither ship available. The Shinsegi had only returned in March from a repair period of about 18 months that began in September 2024, and it reportedly broke down again roughly six months later.

The ships collect signals intelligence on North Korea and track the movements of Chinese and Russian naval forces. They can carry unmanned aircraft for long-range collection, and they are also sent to follow North Korea's illicit ship-to-ship transfers on the high seas. The navy had previously said it alternated maintenance between the pair so that one ship was always ready for operations.

Han said the episode showed the real state of the military's own surveillance and reconnaissance capability. He argued that an accurate assessment of South Korean forces should come before any claim that wartime operational control could be transferred from the United States almost immediately. Military authorities countered that intelligence collection does not depend on any single asset, so the gap was not significant. A follow-up report by Issue Valley said the military pointed to land-based, airborne and combined allied intelligence assets that it runs alongside the ships.

The navy generally regards three hulls as the minimum for a steady rotation, with one ship on patrol, one resting and one in maintenance or training. Two additional ships are not expected until the mid-2030s. Observers quoted by the Chosun Ilbo attribute the delay to the Korean Destroyer Next Generation programme, which seeks six 7,000-ton destroyers for an estimated 7.8 trillion won and has taken priority in the shipbuilding budget.

Both vessels belong to the navy's Maritime Intelligence Group, which reports directly to Naval Operations Command and is led by a one-star officer. The group moved its headquarters from the Jinhae naval base to Busan in October 2023, and details of its ships, their locations and personnel are classified. The Shinsegi is a twin-hulled design, while the 114-metre Shingiwon was built under the AGX-II programme. A first ship of the type, the 1,000-ton Shinchonji, served from 1993 until it was retired in December 2013. Both current ships were built as secret projects funded from the National Intelligence Service budget.

Last year the navy said it planned to spend about 1.94 trillion won to acquire two next-generation intelligence ships of 4,000 tons or more by 2035. A military official said at the time that China operates about 12 such vessels and Japan six, and that the existing South Korean pair had limited long-range detection and urgently needed upgraded equipment. The basic design contract for the new class was put out to competitive tender in March, with about 26 months of development planned and service entry projected for around 2035.