Tokyo-based Hitachi has placed a request with Huntington Ingalls Industries (HII) for the delivery of more than a dozen REMUS 300 small uncrewed undersea vehicles (SUUVs). This multi-year agreement highlights the enduring defense collaboration between Japan and the United States, although it has not been disclosed if the procurement is specifically for the Japan Maritime Self-Defense Force (JMSDF).
The REMUS 300, which has been selected by the U.S. Navy under its Lionfish program, is known for its modular architecture, allowing for quick integration of various mission payloads and system upgrades. This adaptability enables mission-specific configurations tailored to diverse operational needs.
The vehicle is powered by a 4.5-kilowatt-hour lithium-ion battery, enabling it to operate for up to 30 hours at depths reaching 305 meters (1,001 feet). With a maximum speed of 5 knots (9 km/h or 6 mph) and a range of 165 kilometers (102 miles), the REMUS 300 is optimized for extended undersea missions. Optional 1.5 kWh and 3.0 kWh battery variants are available, though they offer reduced performance metrics.
Measuring 2.03 meters (6.66 feet) in length, the SUUV is also designed to work in coordination with manned platforms, such as submarines, extending mission reach while minimizing the risk of detection in contested environments.
