USX-1 Defiant / NOMARS
An experimental ship designed without onboard accommodation, undergoing autonomous reliability and endurance demonstrations.
- Country / region
- United States
- Programme status
- Development / trials
- Sources reviewed
- 21 Sept 2026
- Primary domain
- Sea surface
- System type
- Uncrewed surface vessel
- Developer / manufacturer
- Serco-led team / DARPA
- Origin / production countries
- United States
- Other names
- USX-1 Defiant; NOMARS
- Variants / configurations
- Not distinguished in reviewed sources
- Operators / programme customers
- DARPA / US Navy-supported trials
Evidence & current status
Delivered experimental vessels remain distinguished from operational fleet acceptance and future production programmes.
Role & capabilities
- Naval autonomy research
- Modular mission carriage
Specifications in context
- Configuration
- Experimental vessel designed without onboard crew accommodation
Published programme baseline; not a generic figure for other USVs.
Source - Hull / propulsion
- Not established in the reviewed public sources.
Public evidence gap. No estimate or neighbouring variant value has been substituted.
Source - Dimensions
- 180 ft length
Published programme baseline; not a generic figure for other USVs.
Source - Displacement / mass
- 240 metric tonnes lightship
Lightship mass, not loaded displacement.
Source - Payload
- Not established in the reviewed public sources.
Public evidence gap. No estimate or neighbouring variant value has been substituted.
Source - Endurance
- Up to one year without human intervention: design objective
Not a demonstrated continuous deployment.
Source - Range
- Not established in the reviewed public sources.
Public evidence gap. No estimate or neighbouring variant value has been substituted.
Source - Speed
- Trial speed approached 20 knots
September 2025 test observation; not a certified maximum.
Source - Sea state / environment
- Sea state 5 operation advertised by programme
Design claim; survival in higher seas is not equivalent to full mission performance.
Source - Sensors
- Not established in the reviewed public sources.
Public evidence gap. No estimate or neighbouring variant value has been substituted.
Source - Communications / control
- Not established in the reviewed public sources.
Public evidence gap. No estimate or neighbouring variant value has been substituted.
Source - Launch / deployment
- Not established in the reviewed public sources.
Public evidence gap. No estimate or neighbouring variant value has been substituted.
Source