Tokyo-based Hitachi has placed an order with Huntington Ingalls Industries (HII) for the delivery of over a dozen REMUS 300 small uncrewed undersea vehicles (SUUVs). This multi-year agreement reflects the ongoing strong defense ties between Japan and the United States. It remains unclear whether the procurement is directly linked to the Japan Maritime Self-Defense Force. The REMUS 300, selected by the US Navy for its Lionfish program, features a modular design that supports rapid payload changes and mission-specific upgrades. The SUUV can dive to depths of 305 meters and operate for up to 30 hours, powered by a 4.5-kilowatt-hour Lithium-ion battery. It offers a top speed of 5 knots and a range of 165 kilometers. Lower-capacity battery options reduce its performance. Measuring 2.03 meters in length, the vehicle can also collaborate with crewed platforms like submarines to extend mission range and minimize detection risks.
