REMUS (100 / 300 / 620) at Groton, Connecticut, USA

Huntington Ingalls Industries (NYSE: HII), America's largest military shipbuilder with more than 42,000 employees, makes the REMUS family of autonomous undersea vehicles through its Mission Technologies division, the legacy-prime contrast to the new-defense maritime startups Saronic and Anduril. The REMUS line, whose lineage dates to 2001 from Hydroid and Woods Hole Oceanographic Institution heritage, came to HII through its $350 million acquisition of Hydroid that closed on March 26, 2020, bought from Norway's Kongsberg, and spans the REMUS 100, 300, 600, and the newer REMUS 620 introduced in 2022 with up to 110 hours of endurance and 275 nautical miles of range, used for mine countermeasures, hydrographic survey, intelligence, and electronic warfare.

The registry records it at production, mature-fielded maturity, the highest in the maritime set, on the strength of an order for up to roughly 200 REMUS-class vehicles, a NOAA order for REMUS 620 units delivered in 2024, an international order, and, most significantly, operational fielding: in June 2025, in the Yellow Moray demonstration, HII conducted the first forward-deployed torpedo-tube launch and recovery of a REMUS 600 from the submarine USS Delaware across three fully autonomous sorties, followed by a new Defense Innovation Unit contract for a submarine Torpedo Tube Launch and Recovery system. Its autonomy is decades-mature and operationally demonstrated, the lowest claimed-versus-verified risk in the maritime set, while the TTLR contract value, the exact total REMUS 620 fleet delivered, and the full quantity delivered under the up-to-200 ceiling are not verified.