XV Excalibur
The Royal Navy's Project Cetus extra-large underwater technology demonstrator.
- Country / region
- United Kingdom
- Programme status
- Development / trials
- Sources reviewed
- 20 Sept 2026
- Primary domain
- Underwater
- System type
- Autonomous underwater vehicle
- Developer / manufacturer
- MSubs
- Origin / production countries
- United Kingdom
- Other names
- Project Cetus; Cetus XLUUV
- Variants / configurations
- Named configuration; see the evidence and specification notes
- Operators / programme customers
- Royal Navy Fleet Experimentation Squadron — demonstrator
Evidence & current status
The Royal Navy explicitly describes Excalibur as a non-operational demonstrator. Delivery is not treated as combat or patrol service.
Role & capabilities
- Undersea autonomy experimentation
- Payload integration trials
- Crewed/uncrewed integration research
Specifications in context
- Configuration
- Extra-large autonomous underwater demonstrator
Published specification for the cited configuration; payload, environment and speed affect performance.
Source ↗ - Hull / propulsion
- Not established in the reviewed public sources.
Public data gap; no estimate or neighbouring variant value substituted.
Source ↗ - Dimensions
- 12 m long; 2 m across
Published specification for the cited configuration; payload, environment and speed affect performance.
Source ↗ - Displacement / mass
- 19 tonnes displacement
Published specification for the cited configuration; payload, environment and speed affect performance.
Source ↗ - Payload
- Bespoke experimental payload accommodation
Published specification for the cited configuration; payload, environment and speed affect performance.
Source ↗ - Endurance
- Not established in the reviewed public sources.
Public data gap; no estimate or neighbouring variant value substituted.
Source ↗ - Range
- Not established in the reviewed public sources.
Public data gap; no estimate or neighbouring variant value substituted.
Source ↗ - Speed
- Not established in the reviewed public sources.
Public data gap; no estimate or neighbouring variant value substituted.
Source ↗ - Operating depth
- Not established in the reviewed public sources.
Public data gap; no estimate or neighbouring variant value substituted.
Source ↗ - Sensors
- Not established in the reviewed public sources.
Public data gap; no estimate or neighbouring variant value substituted.
Source ↗ - Communications / control
- Not established in the reviewed public sources.
Public data gap; no estimate or neighbouring variant value substituted.
Source ↗ - Launch / deployment
- Not established in the reviewed public sources.
Public data gap; no estimate or neighbouring variant value substituted.
Source ↗