HII (NYSE: HII) announced that the U.S. Defense Innovation Unit (DIU) has recognized the successful completion of its Production-Ready, Inexpensive, Maritime Expeditionary (PRIME) prototype project, featuring the Watcher small Unmanned Surface Vessel (sUSV) built in partnership with MetalCraft Marine.

The recognition follows HII's delivery and sea testing of two autonomous Watcher ROMULUS-25 vessels in December 2025 under a DIU contract to develop smaller-form-factor autonomous surface vessels for the U.S. Marine Corps.

In a memorandum to HII, DIU stated that the Watcher sUSV "successfully demonstrated its appropriateness to address the Department of the Navy's operational need for sUSV interceptors, capable of autonomously transiting hundreds of miles through contested waterspace, loitering in an assigned operating area while monitoring for maritime surface threats, and then sprinting to interdict a noncooperative, maneuvering vessel."

The DIU memorandum concluded that HII achieved the prototype's key technical goals and success metrics, supporting a potential transition to production under Other Transaction Authority (OTA) prototype agreements.

The two vessels completed at-sea testing across multiple operational scenarios, including contractor demonstrations, government-led autonomy assessments, seakeeping and performance evaluations, and degraded-environment testing.

The Watcher is powered by HII's Odyssey Autonomous Control System, which the company says enables intelligent navigation, mission planning, and multi-domain autonomous operations. The ROMULUS-25 platform can carry payloads of up to 1,000 pounds and operate at ranges of up to 1,000 nautical miles.

The PRIME initiative drew 116 solution briefs in open competition before HII was selected to design, build, and demonstrate its solution.

Duane Fotheringham, president of the Unmanned Systems group within HII's Mission Technologies division, said the milestone reflects "HII's strategy to rapidly transition innovative technologies from concept to operational capability."