Huntington Ingalls Industries (HII) has wrapped up initial production of its Lionfish unmanned underwater vehicle for the US Navy, completing the final deliveries under the program’s base-year contract. The initiative supports the Navy’s transition toward autonomous undersea systems designed to enhance intelligence, surveillance, and warfare missions in contested maritime environments.
Awarded in 2023, the Lionfish program is intended to address key undersea warfare requirements, particularly as the Navy fields uncrewed vehicles in support of crewed assets such as Virginia-class submarines. HII finalized production of 42 vehicles by the end of the year, building on earlier deliveries completed in April 2025. Program work is centered at the company’s Pocasset, Massachusetts facility.
The Lionfish UUV is based on HII’s Remus 300, a next-generation autonomous underwater vehicle developed with modular, open architecture to accommodate evolving mission needs. The platform’s compact design—measuring about 10 feet in length and weighing 154 pounds—allows for flexible deployment across multiple naval platforms.
In terms of performance, the Remus 300 offers a maximum range of 103 miles, operates at depths of up to 1,000 feet, and cruises at speeds of around 5 knots. Recharge times range from six to 18 hours, depending on mission configuration. The Navy selected the Remus 300 in 2022 following competitive evaluations, choosing it as a replacement for the Swordfish UUV fleet derived from the older Remus 100 design.
