SonarTech, a South Korean company specialising in sonar, unveiled a unmanned surface vessel (USV) for both anti-submarine warfare (ASW) and mine warfare missions at MADEX 2025, a naval exhibition held in Busan from 28-30 May.
The prototype vessel, painted yellow and called ASW-USV (or ASW-KUSV), is designed for anti-submarine warfare. It would work in conjunction with UAVs, surface ships, maritime patrol aircraft and sonobuoys to detect submarines.
With the vessel’s research and development funded by the Defense Acquisition Program Administration (DAPA), Sungjoon Hong, Strategic Planning Division/Division Director at SonarTech, told Naval News that the vessel would complete its development on 30 June this year.
After its development is finalised, the Republic of Korea Navy (ROKN) is expected to test and evaluate the vessel and its ASW equipment. There is a heavy demand for such unmanned vessels in South Korea’s surrounding waters, especially considering the threat from North Korean submarines and mini-submarines.
Displacing around 2 tonnes, and the 5.8m-long vessel has a wave-piercing hull form made from non-magnetic, fibre-reinforced polymer that reduces the vessel’s acoustic and electromagnetic signatures. The wave-piercing design also reduces fuel consumption, thus improving endurance to around 150 hours.
The hull has a beam of 1.11m and is 1.3m high. Underneath is a 2.4m-long keel and gondola. Powered by both a 50kW electric motor and a diesel generator, SonarTech listed the ASW-USV’s operating speed at 14kt.
SonarTech started this project on 20 December 2021, and a key feature is its twin sonars. There is a long-range active sonar for detection in a 20m-30km range. This is deployed by lowering a vertical array with a transmitter/receiver sensor to a depth of 240m.
Additionally, there is a side-scan sonar fitted on the USV’s underwater gondola for target classification. The sonar can reach a search depth of 150m and width of 600m. Notably, the sonar has eight sensors, the only one of its type in the world, with Hong explaining that this design allows better resolution of the depth dimension of a target thanks to additional sonar returns.
As well as the USV design, SonarTech has worked to localise and improve sonars already in use by the ROKN. The prime example is the modernisation of Thales Type 193 MOD 1 sonars on the navy’s six Ganggyeong-classcoastal minehunters.
Utilising its SEAView-1030 product, the company has come up with an improved display for processing data from sonars. It exhibited one of its 1.83m-high Korean-made operator consoles at MADEX 2025.
The company stated, “SEAView-1030 is the world’s first hull-mounted sonar designed for sea mine hunting, then display its continuous target signals without getting disruption from the interference of other backscatter such as ambient noises, false signals, etc.”
From a normal live sonar feed on the operator’s display, it can be difficult to see through all the clutter, but SonarTech’s new method uses a 60-frame-per-second frequency to clearly identify targets.
Hong said this is a lower-cost but effective mathematical solution as an alternative to using artificial intelligence for sonar data processing.
