U.S. Navy Scales Autonomous UUV Fleet

HII has been awarded an option year production contract by the U.S. Navy to continue manufacturing the Lionfish small unmanned undersea vehicle.

The Lionfish small unmanned undersea vehicle (SUUV) represents the Navy’s first successful transition from an Other Transaction Authority prototype effort to full-scale production. This milestone demonstrates an accelerated application of dual-use commercial technologies to support operational U.S. Department of Defense capabilities. Based on HII’s commercial REMUS 300 platform, the system was originally developed as part of a rapid prototyping initiative in collaboration with the U.S. Navy and the Defense Innovation Unit. It currently stands as the first and only cyber-compliant unmanned underwater vehicle in production for the U.S. Navy.

This latest contract continues the momentum of the five-year program, which could scale to as many as 200 vehicles with a total contract value exceeding $347 million. The program previously marked a major production milestone at the close of 2025 with the completion of the 42nd Lionfish vehicle at HII’s Pocasset facility.

“The decision to exercise this option year production of the Lionfish program reflects the U.S. Navy’s confidence in the platform’s operational performance, reliability and adaptability,” said Duane Fotheringham, president of the Unmanned Systems group in HII’s Mission Technologies division. “Our team remains focused on delivering advanced autonomous systems that provide sailors and marines with critical undersea warfare capabilities in support of evolving mission requirements.”

Designed to address a broad range of undersea warfare missions, the platform supports mine countermeasures, intelligence, surveillance and reconnaissance, anti-submarine warfare, and electronic warfare operations. The underlying REMUS 300 platform utilizes a modular, open-architecture design engineered for multi-mission adaptability. This architecture enables rapid payload integration and future technology upgrades, allowing operators to adapt the system to evolving mission needs while maintaining cost efficiency over the platform lifecycle.

The broader REMUS family of unmanned underwater vehicles has been field-proven across global naval operations. HII has delivered more than 700 REMUS vehicles to over 30 countries, including 14 NATO members. Demonstrating the long-term reliability of the technology, more than 90% of REMUS systems delivered during the past 25 years remain in active service today.