Autonomous surface vessel Defiant christened under DARPA NOMARS program
NewsAugust 12, 2025
EVERETT, Washington. DARPA held a christening ceremony for the USX-1 Defiant, an autonomous unmanned surface vessel (USV) built under the No Manning Required Ship (NOMARS) program, the agency announced in a statement.
The 180-foot-long, 240-metric-ton vessel is designed from the keel up to operate without human crew, with a simplified hull intended to enable faster production and maintenance in smaller commercial shipyards, the statement reads. Defiant is undergoing final systems tests ahead of an extended at-sea demonstration to evaluate reliability and endurance.
According to DARPA, the vessel is built to operate in open-ocean conditions, including sea state 5 without performance degradation, and to resume operations after more severe weather. The NOMARS program seeks to advance the development of fully unmanned ships, reducing reliance on “optionally manned” platforms and demonstrating scalability for U.S. and allied naval use.
Following trials, Defiant will be transferred to the U.S. Navy’s Unmanned Maritime Systems Program Office (PMS 406) for further evaluation. Congress has allocated $2.1 billion for the development and procurement of purpose-built medium USVs, the statement adds.
