NOMARS

NOMARS is a concept for a range of ships and smaller watercraft operating as unmanned surface vessels for the US Department of Defense, developed by the Defense Advanced Research Projects Agency.
The USV concept crafts range in size and form. Examples include:

Sea Hunter, a DARPA-developed trimaran USV launched in 2016.
A dual hulled platform, proposed in a concept by Austal USA.
A single hulled missile ship with a propulsor and steering pod.

By removing the human element from all ship design considerations, NOMARS will demonstrate significant advantages, to include size, cost, at-sea reliability, survivability to sea-state, survivability to adversary actions, and hydrodynamic efficiency.
In 2022, ship designer Serco was selected to develop the NOMARS program through building, testing, and demonstrating the first generation ship.
In December 2024, NOMARS completed a successful first test of at-sea refueling designed for use with the USV Defiant.
USX-1 Defiant, the 180-foot-long, 240-metric ton medium USV, was first seen in public in March 2025 near the Naval [Air Station Whidbey Island|U.S. Navy's Naval Air Station ] Whidbey Island. USX-1 Defiant does not have any mission or combat systems installed onboard and will conduct sea trials in the spring of 2025.