HII expands UK facility, looks to grow European unmanned systems business

The unmanned systems business of HII Mission Technologies will support production and operation of REMUS 300 vehicles (pictured) from its expanded facilities in Portchester, UK. (Richard Scott/NAVYPIX)

HII is doubling the size of its maritime unmanned systems facility in Portchester, UK, as it looks to grow its underwater unmanned vehicle (UUV) and unmanned surface vehicle (USV) business in the UK and elsewhere in Europe.

Announcing the move on 12 January, the US-headquartered company said its expanded operations footprint would support maintenance, training, upgrade, and long-term sustainment for its REMUS UUV and new ROMULUS USV system families for operators across the UK and Europe. It added that the site will “work in close co-ordination with HII's global engineering, production, training, and mission support teams to keep programmes aligned and effective”.

Over 750 REMUS vehicles have been delivered by the unmanned systems business of HII Mission Technologies to date, with systems in service with over 30 countries including 14 NATO members. The UK Royal Navy (RN) is a longstanding user of REMUS UUVs, having received its first REMUS 100 vehicles back in 2002, and in July 2024 awarded HII a three-year GBP8 million contract to support its current inventory of REMUS 100 and REMUS 300 vehicles.

HII announced the development of the ROMULUS family of modular, artificial intelligence (AI)-enabled USVs in September 2025. Powered by HII's Odyssey autonomy control system software, ROMULUS is a reconfigurable design designed to support surface, underwater, and air domains for missions including counter-unmanned air systems; intelligence, surveillance, and reconnaissance; strike; and launch and recovery of UUVs and unmanned aerial vehicles (UAVs). A prototype of the flagship ROMULUS 190 large USV is currently under construction in the United States.