The No Manning Required Ship (NOMARS) program has built a ship designed to operate autonomously for long durations at sea. Construction of the prototype unmanned surface vessel (USV), USX-1 Defiant, was completed in February 2025.

Defiant is a 180’, 240-metric-ton lightship that will undergo extensive in-water testing, both dockside and at sea. She is scheduled to depart for a multi-month at sea demonstration in spring 2025.

The NOMARS program aims to challenge the traditional naval architecture model, designing a seaframe (the ship without mission systems) from the ground up with no provision, allowance, or expectation for humans on board. By removing the human element from all ship design considerations, the program intends to demonstrate significant advantages, to include: size, cost, at-sea reliability, greater hydrodynamic efficiency, survivability to sea-state, and survivability to adversary actions through stealth considerations and tampering resistance.

The launch followed testing of the at-sea refueling capabilities in December 2024. The team demonstrated all parts of the system CONOPs while underway, including passing the lead-line to the refueling side, passing and connecting the refueling probe to the USV side and pumping water.