HII’s USV prototype hits 30% completion, on track for 2026 sea trials

December 12, 2025, by Fatima Bahtić

US defense major HII has announced that construction of its first ROMULUS unmanned surface vessel (USV) has reached 30% completion, staying on schedule for sea trials in late 2026.

This ROMULUS prototype is the first in HII’s modular, AI-enabled ROMULUS USV line. The ships are engineered for rapid, repeatable production and high endurance at sea. With speeds over 25 knots and a range of 2,500 nautical miles, all ROMULUS USVs are designed for mission flexibility.

The USVs are designed to meet the current and emerging requirements of the US Navy, US Marine Corps, joint forces, and allies. They will support missions including intelligence, surveillance and reconnaissance, counter-unmanned air systems, mine countermeasures, strike, and the launch and recovery of unmanned underwater vehicles (UUV) and unmanned aerial vehicles (UAV).

Paired with HII’s REMUS UUVs, ROMULUS, which is being developed with support from HII’s Dark Sea Labs Advanced Technology Group. extends undersea reach and supports a scalable dual-domain force package built for distributed maritime operations.

Furthermore, ROMULUS is built around Odyssey ACS, HII’s autonomy suite, which enables sustained open-ocean autonomy, multi-agent swarming, modular payload integration, and manned-unmanned teaming. ROMULUS platforms will also feature integrated capabilities from Shield AI, Applied Intuition, and C3 AI for enhanced autonomous performance and lifecycle sustainment.

In November, HII and Shield AI announced that they had completed the first major test of their integrated autonomy solution aboard HII’s ROMULUS 20 USV, marking a key step toward operational deployment of the AI-enabled ROMULUS fleet.