South Korea’s Hanwha Group and U.S.-based Vatn Systems team up to co-develop low-cost autonomous underwater drones for the U.S. Navy, supporting Washington’s drive for scalable undersea systems to counter China’s growing presence in the Indo-Pacific.
South Korea’s Hanwha Group and U.S. startup Vatn Systems have agreed to jointly develop autonomous underwater drones for the U.S. Navy to counter China’s growing maritime presence in the Indo-Pacific, Reuters reported on December 10, 2025. The deal follows Hanwha’s recent $60 million investment in Vatn and aims to rapidly field low-cost, torpedo-shaped vehicles capable of both surveillance and strike missions.
The partnership centers on Vatn’s Skelmir S6, a Compact Modular Underwater Effector. The man-portable drone weighs 50–60 pounds, measures 6 inches in diameter, and carries a 10–20 pound payload. It can travel at speeds up to 20 knots, with a range of 20 nautical miles and an operating depth of around 100 meters, prioritizing speed and mass deployment over endurance.
Designed as an expendable asset, the S6 can be controlled by a single operator using an Android Tactical Assault Kit plug-in, allowing hundreds of drones to be monitored and deployed simultaneously. The platform supports kinetic warheads, electronic warfare, cyber payloads, and various sensor packages without requiring deep integration with host vessels.
Cost-effectiveness is key. At roughly $75,000 per unit, the S6 is far cheaper than larger autonomous underwater systems. This allows carrier strike groups or Marine littoral regiments to saturate chokepoints with swarms, creating mine-like ambush zones, screening high-value units, or hunting enemy submarines using attritable sensors and torpedoes.
Hanwha contributes extensive naval experience, including submarines, mine countermeasure systems, unmanned maritime vehicles, and autonomous surveillance AUVs. Its shipyard capacity in Korea and the U.S., including Philly Shipyard, enables scaling Vatn’s small-batch innovation into fleet-level production.
For the U.S., the partnership supports the Pentagon’s Replicator initiative, which seeks thousands of attritable autonomous systems to counter China’s numerical advantage. Skelmir-style swarms are cheap, fast, hard to track, and suitable for GPS-denied, jammed littorals. Adding Hanwha as a co-producer diversifies the U.S. undersea industrial base and strengthens allied integration in emerging autonomy supply chains.
Seoul benefits by integrating into U.S. undersea weapons programs, gaining technology transfer in autonomy software, networking, and Navy certification standards. The same systems can be adapted for Korean needs, from mine hunting and port defense in the Yellow Sea to layered anti-infiltration barriers, complementing Hanwha’s larger ASW UUVs and mine warfare USVs.
China has sanctioned Hanwha for its U.S. shipbuilding expansion, but Seoul’s deeper cooperation with Washington demonstrates willingness to endure pressure for a closer defense-industrial alliance. For the U.S., co-branded allied production strengthens deterrence and facilitates deployment with Indo-Pacific partners.
The Hanwha-Vatn agreement represents a potential model for future undersea weapons: small, fast, software-defined effectors produced in the thousands. If successful, Skelmir swarms could become standard for U.S. and Korean naval forces, creating a complex underwater threat environment from the Taiwan Strait to the Sea of Japan.
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