Naval & Maritime defence companies in the UK

We track 22 naval and maritime companies in the UK, most of them in Plymouth and London. 1 of them is hiring now, with 5+ open roles. Among them are MARSS Group, ACUA Ocean and Blueprint Subsea.

All Naval & Maritime Companies in the UK

MARSS Group logo
MARSS GroupLondon · Naval & Maritime
5 roles

Builds AI-powered command and control systems for counter-drone defence, maritime security and critical infrastructure protection, deployed at over 60 sites worldwide.

ACUA OceanPlymouth · 11-50 employees · Naval & Maritime
No listed roles

Designs and operates the Pioneer-class small waterplane area twin hull USV for anti-submarine warfare, maritime ISR and critical national infrastructure monitoring, becoming the UK's first Remotely Operated Unmanned Vessel certified under Workboat Code 3 in 2025.

Blueprint Subsea11-50 employees · Naval & Maritime
No listed roles

Blueprint Subsea develops compact underwater acoustic sensors, imaging sonars, acoustic positioning beacons and diver navigation systems for subsea and defence markets.

Cambridge PixelRoyston · 11-50 employees · Sensors & EW
No listed roles

UK developer of radar signal processing, tracking and display software used by defence and maritime system integrators, supporting a wide range of modern and legacy radars with hardware-agnostic SDKs. Serves naval, air and security customers worldwide.

Chess DynamicsHorsham · 201-500 employees · Sensors & EW
No listed roles

UK defence systems company designing electro-optical surveillance, targeting, fire-control and counter-UAS systems for land, maritime and air-defence missions.

Clearwater Hydroacoustics logo
Clearwater HydroacousticsBrasted · 1-10 employees · Naval & Maritime
No listed roles

Dstl spin-out making SonarBell, an omni-directional passive sonar reflector used for asset and location marking, sonar testing and performance checking. Battery-free with no electronics for underwater defence applications.

ForcysPortsmouth · 51-200 employees · Naval & Maritime
No listed roles

Forcys develops underwater defence technology, bringing together sonar, maritime sensing and autonomous-system expertise for naval and subsea security missions.

HonuWorxAberdeen · 11-50 employees · Naval & Maritime
No listed roles

Aberdeen subsea robotics company developing uncrewed underwater deployment platforms, Loggerhead systems and cloud-edge control software for offshore operations.

JET Connectivity11-50 employees · Communications
No listed roles

Maritime connectivity company building AI-driven 5G mesh networks for offshore, autonomous and contested environments. Selected for NATO DIANA Mission Track in 2026.

Kraken Technology GroupLondon · 51-200 employees · Naval & Maritime
No listed roles

British company developing disruptive maritime capabilities including advanced littoral, surface, and subsurface autonomous platforms for defence and commercial applications using cutting-edge composite materials and rapid prototyping.

K3 Scout
K3 Scout
An 8.4m autonomous USV with 55-knot top speed, 650 NM range, and 600 kg modular payload capacity, available in three variants up to the 18.6m MAX with 10,000 kg payload and 2,000 NM range.
K4 Manta
K4 Manta
An all-electric foiling uncrewed surface-subsurface vessel (USSV) that transits at up to 45 knots on the surface before submerging to 10m depth for covert ISR, loitering, or strike missions.
K5 Kraken
K5 Kraken
A 15.25m armed maritime precision engagement platform hitting 65 knots, carrying twin 7.62mm remote weapon stations, four multi-role missiles, and four aft-launched torpedoes for crewed or autonomous operations.
Malloy AeronauticsMaidenhead · 51-200 employees · Drones & UAV
No listed roles

UK heavy-lift UAS manufacturer building all-electric VTOL logistics drones for military, government and commercial missions, including battlefield resupply and last-mile operations.

Marine AI logo
Marine AIPlymouth · 11-50 employees · Naval & Maritime
No listed roles

Maritime autonomy software for uncrewed surface vessels, including GuardianAI for defence applications. Technology powered the Mayflower Autonomous Ship's transatlantic crossing and is used by Plymouth's USV cluster.

MSubs logo
MSubsPlymouth · 51-200 employees · Naval & Maritime
No listed roles

Designs, builds and operates manned and unmanned submersibles for military and commercial markets, including extra-large autonomous test submarines awarded a £1 million DASA contract for the Royal Navy. Operates from Plymouth with a sister facility in Round Rock, Texas.

Robosys AutomationSouthampton · 11-50 employees · Naval & Maritime
No listed roles

Develops VOYAGER AI maritime autonomy software that converts crewed vessels into uncrewed surface vessels with IMO Degree 4 autonomy, sold to government and defence customers. Opened Southampton UK headquarters in 2025 with offices in USA, Canada and India.

SEA-KIT InternationalTollesbury · 11-50 employees · Naval & Maritime
No listed roles

UK builder of remotely controlled uncrewed surface vessels with defence and security configurations for maritime missions that reduce personnel risk at sea.

SeeByteEdinburgh · 51-200 employees · Naval & Maritime
No listed roles

SeeByte develops software for uncrewed and autonomous maritime systems, including mine-countermeasure toolboxes, mission autonomy and target-recognition systems.

Sirius InsightPortsmouth · 11-50 employees · Naval & Maritime
No listed roles

Sirius Insight develops AI-enabled maritime surveillance and decision-support systems for monitoring coastal, port and offshore environments.

SubSea CraftPortsmouth · 51-200 employees · Naval & Maritime
No listed roles

UK maritime technology company developing advanced surface and subsurface craft, including VICTA, MARS USV and CADDIS systems for contested littoral and defence missions.

UFORCE logo
UFORCELondon · 11-50 employees · Drones & UAV
No listed roles

UK-registered defence platform unifying combat-proven Ukrainian unmanned systems, including MAGURA USVs, Nemesis strike drones and Fury ground robots. Raised $50M seed at a $1B valuation, with Ben Wallace on the board.

WaiV Robotics logo
WaiV Robotics1-10 employees · Naval & Maritime
No listed roles

Develops an autonomous self-levelling landing platform that lets VTOL drones take off and recover from moving vessels in high sea states without hardware modifications. Emerged from stealth in 2026 with a €6.4 million seed round.

ZelimEdinburgh · 11-50 employees · Naval & Maritime
No listed roles

Zelim develops intelligent maritime safety and rescue technology to make oceans, seas and waterways safer. The company provides advanced detection, tracking, and alerting systems including ZOE (intelligent detection system), SWIFT (rapid man overboard recovery system), and GUARDIAN (uncrewed rescue vessel). Zelim serves the cruise/passenger and offshore energy sectors with ISO 9001 certified solutions.

ZeroUSV logo
ZeroUSVPlymouth · 1-10 employees · Naval & Maritime
No listed roles

ZeroUSV designs, builds and operates autonomous uncrewed surface vessels for defence, security, survey and scientific offshore missions.

Oceanus12
Oceanus12
Transportable autonomous USV designed around a 40-foot ISO footprint, with modular payload integration and multi-week endurance.
Oceanus17
Oceanus17
Larger OCEANUS platform for longer endurance missions, heavier payload integration and harsher sea states while remaining road transportable.
Autonomous Glider Deployment
Autonomous Glider Deployment
USV-enabled system-of-systems capability for deploying subsea gliders from an uncrewed surface vessel.