Skip to content
You can now search across every topic, entity and event.What's new
XV Excalibur
ProductGB

XV Excalibur

The Royal Navy's 12-metre CETUS-programme extra-large uncrewed underwater vehicle, built by M Subs.

Last refreshed: 3 July 2026 · Appears in 1 active topic

Key Question

How does a GBP6.68m trial vessel connect to a GBP5bn navy drone plan?

Timeline for XV Excalibur

#7 16 Jul

Type 91 to 94 robot fleet takes shape

Autonomous Systems: Land & Sea
#5 24 Jun

Entered a trials contract as the largest XLUUV the Royal Navy has trialled

Autonomous Systems: Land & Sea: A £6.68m trial holds the subsea money
View full timeline →
Follow Autonomous Systems: Land & Sea →

Background

XV Excalibur is the extra-large uncrewed underwater vehicle (XLUUV) at the centre of the Royal Navy's CETUS programme. The Submarine Delivery Agency awarded M Subs a GBP6,680,147 sole-source contract on 24 June 2026 to trial it.

At 12 metres long and 19 tonnes, Excalibur is the largest uncrewed underwater vessel the Royal Navy has trialled, built by M Subs of Plymouth as CETUS's sole designer; the trial runs to 1 May 2028.

Excalibur is the funded, dated reality sitting under the Type 93 class the 30 June Defence Investment Plan named alongside three other uncrewed classes, a contract three orders of magnitude smaller than the plan's headline GBP5bn commitment.

Common Questions
What is XV Excalibur?
The Royal Navy's largest uncrewed underwater vehicle to date, a 12-metre, 19-tonne extra-large drone built by M Subs under the CETUS programme.Source: UK Ministry of Defence
How much did the Royal Navy pay for the XV Excalibur trials?
GBP6,680,147, awarded sole-source to M Subs on 24 June 2026 for trials running to 1 May 2028.Source: UK Ministry of Defence
How does the XV Excalibur trial connect to Britain's Type 93 warship?
Excalibur is the CETUS vehicle the Type 93 class is built around, but its trial runs to 2028, so no Type 93 fielding decision can use its data before then.Source: UK Ministry of Defence