Unmanned Underwater Vehicles: A Strategic Opportunity


    As on land, the sea is subject to a logic of appropriation and sovereignty. The same applies to the abyss. Today, the market for underwater drones such as Unmanned Underwater Vehicles (UUVs) is growing significantly, due to their strategic capabilities.

    The missions UUVs can assist with are varied:

    1. Mine clearance (detection and neutralisation),
    2. Intelligence
    3. Surveillance
    4. Reconnaissance
    5. Anti-submarine warfare (ASM).

    However, the objective is to improve the capabilities of Unmanned Underwater Vehicles, into fully autonomous AUVs (Autonomous Underwater Vehicles). Advances in Artificial Intelligence (AI) technology make this possible.

    The new technological developments in underwater technology thus focus on increasing:

    • the autonomy
    • agility
    • storage capacity of drones

    Whilst limiting their energy consumption. In this article, we will look at why the seabed is of major strategic interest, and the military use of UUVs.

    1.0 The highly strategic seabed

    1.1. Natural Resources

    The ocean domain is a reservoir of resources. There are mineral resources (aggregates, nodules, sulphurous clusters, crusts), energy resources (oil and gas, marine renewable energies), and biological resources (biodiversity, strains, molecules) (source). With the need for raw materials growing exponentially, the metals on the seabed are therefore a strategic resource. Indeed, such materials are strategic due to their use technologies, and in the technology and defence industries. New civil or military technologies also use so-called rare or strategic metals.

    An Unmanned Underwater Vehicle being transported
    Img; An Unmanned Underwater Vehicle being transported; via the Office of Naval Research on Flickr

    1.2. Available Minerals

    Thus, the deep sea is full of valuable mineral resources, buried at depths ranging from 400 to 6000 meters. There are three types of minerals (source)

    • Polymetallic nodules: from 4000 to 6000 m, which contain iron and manganese, copper, cobalt and nickel.
    • Cobalt crusts: from 800 to 2500 m. which contain cobalt but also precious metals (platinum) and rare metals (like zirconium).
    • Sulphide clusters or hydrothermal sulphides: are formed from 800 m depth and are rich in copper, zinc, gold, silver, cobalt, lead, barium, cadmium, antimony, and mercury.

    But there are also (source):

    • Diamonds: Appreciated for a long time for its hardness, diamond is used in particular to manufacture cutting tools (mirror industry, machining) or drilling heads (oil and mining industries). In the armaments sector, manufacturers use diamonds to form missile caps. It resists well the heating of the missile head in the air while remaining transparent to infrared, ultraviolet and, to a lesser extent, X-rays and microwaves. Its resistance to radiation, far superior to that of silicon, is of interest to the military, the nuclear industry, astronomy, and nuclear medicine.
    • Phosphates: the accumulation of organism remains in the sediments can lead to phosphorus nodules. Concentrations reach 12 to 18% phosphate. Known underwater reserves represent about 50 years of current world requirements.
    • Placers: It is the accumulation of heavy minerals (tin, gold, platinum, titanium, etc) in the sediments. The production of tin of marine origin already reaches 7% of the world total, with Malaysia, Thailand and Indonesia being the main producers.

    Thus, in the abyss, we find copper (essential in electrical components), manganese (which reinforces the properties of copper and steel), nickel (aeronautical superalloys and stainless steel), and silica (manufacture of optical glass, and telephone batteries).

    1.3. Underwater Cables and Pipes

    Underwater cables carry the production of offshore gas and oil infrastructures and wind farms, as well as 99% of the data exchanged between the world’s telecommunication networks (source). Most intercontinental communications, financial flows, and access to telestored data (from the cloud) depend on them. These cables include everything from personal communications to financial transactions a sensitive national security data. They are therefore important strategic levers for states. So much so, that the data is described as the ‘new oil’, and the cables as veritable trans-oceanic pipelines. States are thus becoming aware of the increasing vulnerability of these submarine cables.

    Therefore, the threat to undersea cables is multifaceted. Sabotage, espionage, and foreign adversaries could track their whereabouts to sabotage them and cut rivals off from communications. For example, there has long been suspicion that Moscow is actively targeting these cables for spying purposes (source). Further, The Nordstream underwater gas pipelines were sabotaged in September 2022, with no clear answer who was behind it.

    1.4. The Unexplored Seabed

    The one who masters the depths masters the surface. To date, more than 6000 people have climbed Everest, 12 men have walked on the moon, but only four have dived more than 10,000 metres into the Mariana Trench, the deepest place on Earth (source). Depth, pressure, water temperature, poorly understood water mass movements in the depths, and tectonic activity are all obstacles to access. Beyond a depth of 2000 metres, reaching the abyss requires extremely specialised technical skills. At 3500 metres, the deepest oil wells are located. Scientists are currently conducting research between 1000 and 5000 metres. Nevertheless, the ‘useful horizon’ in terms of resources is around 6000 metres (source).

    1.4.1 The role of GAFAMs

    States see it as a way to extend their sovereignty. Private players such as the Google, Apple, Facebook, Amazon, Microsoft (GAFAMs) are laying submarine cables with colossal budgets, and tourist underwater robots capable of descending to 200 metres are being sold for as little as 2000€. Also, from the bottom of the oceans, players can take advantage of technological progress and an environment conducive to concealment. Therefore, states have great interest in the development of sensors and weapons projects for the air-sea space (source). Finally, the development of artificial intelligence (AI) is driving the market for underwater exploration robots and drones.

    1.4.2 Protection of underwater Infrastructure

    • Protection of underwater infrastructure;
    • anti-submarine warfare;
    • mine warfare;
    • search and recovery of objects damaged at sea
    • development of hydrography and oceanography;
    • exploitation and exploration of underwater resources;
    • military ISR;
    • concealment;
    • scientific exploration and control of the abyss;

    are all reasons for a state to have a military intervention capability on the seabed.

    There are many technological innovations in the field. We will focus now on underwater drones, more properly called underwater vehicles. UUVs (Unmanned Underwater Vehicles) fall under two categories: ROVs (Remotely Operated Vehicles), or AUVs (Autonomous Underwater Vehicles).

    2.0. Why Unmanned Underwater Vehicles?

    The deep ocean demands that a maritime force be capable of surveilling and acting in and over large geographic areas just like the ocean surface above it.

    2.1. Focus on ROVs

    ROVs are unoccupied, usually highly swift underwater robots operated by a crew aboard a vessel. They are common in deep water industries and scientific exploration. An ‘umbilical’ cable carries power and control signals to the vehicle and video, status, and other sensory data back to the operators. Some ROVs have specialised cameras and lighting. Additional equipment may include:

    • Sonars
    • Magnetometers
    • Still camera
    • Manipulator or cutting arm
    • water samplers and devices that measure
      • water clarity water temperature
      • water density
      • sound velocity
      • light penetration (source).

    They can be used in different fields:

    1. Energy
    2. Military
    3. Scientific research
    4. Search and rescue
    5. Marine science
    6. Educational outreach. But let’s focus on the military field.

    As their capabilities grow, ROVs are also increasingly being adopted by navies, coast guards, and port authorities around the globe. Police departments and search and recovery teams also increasingly use ROVs. Underwater ROVs have traditionally been cumbersome, expensive, and difficult to deploy quickly. But now, some ROVs can have a deployment time of under a minute. This is a key factor that has prompted many navies, police forces, and search and rescue groups to use ROVs in their day-to-day operations.

    Therefore, ROVs are useful for a variety of underwater inspection tasks such as:

    2.1.1. Explosive Ordnance Disposal (EOD)

    Military clearance divers carry out dangerous tasks including deploying a shaped charge to disarm a mine or examining and disrupting a Waterborne Improvised Explosive Device (WBIED). These tasks are still done by humans because they require high fidelity perception and dexterous intervention capabilities not previously available through a remote solution. Recently, with the release of more dexterous, compact manipulator arms, military organisations are investigating ways for ROVs to start to do some of these more dangerous tasks.

    2.1.2. Port Security

    The passageways between countries and regions are getting busier every day. With more unknown vessels entering port, each one needs to be inspected for potential threats. For example, countries like Saudi Arabia and other Gulf States are increasingly worried about Irani incursions in its ports.

    2.1.3. Mine Countermeasures

    Underwater vehicles can scout underwater minefields and possibly disarm naval mines. They may reduce, but not eliminate, the need for specialized diver teams to reconnoitre, identify, and demine potential landing beaches for amphibious warfare operations. However, as technology develops the needs for frogmen such as the elite operators of DEVGRU might become obsolete.

    2.1.4. Smuggling

    It is possible to hide contraband in the bottom of a ship’s hull or inside its propellers. But with an ROV, port security professionals can quickly receive live video from underneath a ship. Once again, this avoids putting a diver’s life at risk.

    2.1.5. Search and Recovery

    Drownings often occur in bodies of water that are also extremely dangerous for divers. The availability of an ROV for immediate deployment minimizes the risk to divers. An ROV can also work in large areas in combination with a dive team. When a person is located, divers can either follow the ROV lanyard to the victim, use the grabber to recover the victim or deploy a buoy. Recovery operations include scenarios such as recovering a downed aircraft or drowning victims. Teams of highly trained military or civilian divers have historically performed these tasks. Recently, ROVs have been able to assist and, in some cases, take over these high-risk tasks.

    2.1.6. Training

    Military training programmes currently use ROVs. Many forces have training exercises that require specific diving exercises or the execution of underwater manoeuvres. An ROV allows all movements and interactions of the students to be recorded for later review and personal improvement exercises.

    2.2. What about Autonomous Underwater Vehicles (AUV)?

    AUVs can react to their environment and make decisions without a human operator, which is not the case for ROVs. Artificial intelligence then comes into play. They can perform underwater survey missions such as detecting and mapping wrecks, rocks and submerged obstructions that may pose a hazard to military, commercial and recreational navigation. AUVs can conduct most of the tasks of ROVs.

    Therefore, they are most often used in conditions that the United States calls the ‘three Ds’:

    1. Boring
    2. Dirty
    3. Dangerous.

    Indeed, AUVs may be particularly suited to long-duration missions that could test the physical endurance of onboard human operators. Additionally, AUVs provide advantages in missions that pose a high risk of:

    • injury;
    • death:
    • capture of onboard human operators.

    2.3. What are the Advantages?

    Whilst ROVs are limited in size and dependent on human action, Autonomous underwater vehicles can perform specific missions.

    2.3.1. Sub-Hunting

    This kind of drone can perform anti-submarine operations by actively searching and tracking enemy submarines, without endangering manned surface vessels or submarines. The use of underwater drones for anti-submarine purposes will thus minimize the need to commit manned warships for such operations.

    2.3.2. Nuclear Capable

    More significantly, underwater drones can become strategic weapons when loaded with nuclear weapons. Such nuclear-armed underwater drones can bypass enemy missile defences by travelling underwater, slipping near or into major coastal cities, ports and naval bases for attack purposes.

    2.3.3. UUVs and Intelligence Surveillance Reconnaissance (ISR)

    Major powers develop and deploy unmanned underwater vehicles (UUVs). Indeed, underwater drones meet the increasing needs in the fields of maritime intelligence, surveillance and reconnaissance. In fact, the use of unmanned technologies is not a new concept, but how UUVs are developed and used to operate in the vast oceans will influence the ability of nations to operate in their national waters and around the world.

    For example, the proliferation of underwater drones in the Pacific region is changing the face of undersea warfare, as the region’s maritime environment poses unique operational challenges to undersea operations.

    3.0. Positions of Stakeholders on Unmanned Underwater Vehicles?

    If we are witnessing a general remilitarisation of the oceans and seas, this trend is being replicated at the bottom of the sea. The great powers are engaged in a deafening underwater competition: each is increasing its capacities and setting up operational systems to prepare a seabed warfare.

    3.1. United States

    The US Navy is integrating Subsea and Seabed Warfare (SSW) into their Full Spectrum Undersea Warfare (FSUSW). American defence companies such as General Dynamics Mission Systems are proposing their innovations as part of an overall forward-looking vision for seabed warfare. From 2021 to 2025, the US Navy would like to spend $1.9 billion on UUVs. It is expected to spend $941 million on USVs (unmanned surface vehicles) and UUVs in 2021 alone, an increase of 129% over 2019 (source). The US Navy hopes to develop a ‘shadow fleet’ of unmanned ships to make up for its numerical deficit in the face of the rising Chinese Peoples Liberation Army Navy (PLAN).

    US Navy Personnel retrieve an Unmanned Underwater Vehicle
    Img; US Navy Personnel retrieve an Unmanned Underwater Vehicle; via the US Navy on Flickr

    3.2. Russia

    Russia hopes to maintain a cost-effective oceanographic picture of the surrounding seas, particularly in the Arctic Ocean. Unmanned Underwater Vehicles also meet the need to defend submarines against NATO’s sophisticated torpedoes and mines. Moreover, Russia appears to be the only country in the world with the capability to integrate nuclear turbine generators into unmanned aerial vehicles (UAVs) or small underwater installations. It is already deploying the Poseidon strategic intercontinental autonomous torpedo powered by a nuclear turbine generator. These small reactors can also supply electricity to charging stations for drones.

    3.3. China

    Although China’s fleet of AUVs is still primarily research experiments and early-stage prototypes, PLA Navy scientific research documents (PLAN) indicate that China is very interested in these technologies. The PLAN primarily focuses on using AUVs for maritime surveillance and reconnaissance, mine warfare and countermeasures, submarine cable inspection and anti-submarine warfare (source).

    Moreover, advances in unmanned vehicle research may also permit the PLAN to use AUVs to tap or sever undersea fiber-optic cables in a conflict, which concentrates near northern Taiwan. These cables are crucial not just for information dissemination in Taiwan, but also for the trans-Pacific data exchanges that facilitate global internet access.

    Finally, in the future, the Chinese military may use large AUV models for anti-submarine warfare (ASW) and operations near the seabed. Indeed, the control of strategic maritime areas for China, such as Jiangsu Province, may explain this desire to militarise the seabed. With a coastline of more than 1000 kilometres, Jiangsu province faces Japan and South Korea.

    3.4. France

    France, with the world’s largest submarine domain, cannot remain aloof from this new strategic space. On the 14th of February 2022, the French Minister of the Armed Forces presented a new seabed strategy.

    “The seabed is a new area of power relations that we must master in order to be ready to act, to defend ourselves and, if necessary, to take the initiative, or at least to retaliate”.

    The French Navy’s ‘Mercator’ strategic plan confirms this as a priority within the French Military Programming Law 2019-2022, with a budget of €2.9 million. For France, the objective is to have a permanent large-scale operational capacity from 2025.

    3.5. United Kingdom

    Like other nations, British defence needs a greater presence in the undersea battlespace. The Royal Navy needs fully autonomous systems that can sense, understand, and decide without human intervention. These systems will increase in the undersea battlespace and take over the boring, dirty, and dangerous tasks of manned platforms.

    Britain is seeking to develop an autonomous undersea force (its “force mix”).  As part of its Defence and Security Accelerator (DASA) program, the MOD awarded Marlin Submarines Ltd a procurement contract. This contract contains provisions to develop an autonomous version of an Extra Large Unmanned Underwater Vehicle (XLUUV). The XLUUV is a two-stage project with a total value of £2.4 million.

    4.0. Future Plans on Unmanned Underwater Vehicles

    4.1. United States

    The US Navy wants to develop and procure Extra-Large Unmanned Undersea Vehicles (XLUUVs). The US Navy established the XLUUV program, also known as the Orca program, to address a Joint Emergent Operational Need (JEON). The Navy defines XLUUVs as UUVs with a diameter of more than 84 inches, meaning that XLUUVs may be too large to launch from a manned Navy submarine.

    4.2. Russia

    According to the information published by Izvestia (a major Russian newspaper), in late 2021 the Russian Ministry of Defense approved a test plan for the new unmanned underwater vehicle (UUV) Klavesin-2R-PM in the Far East, after being tested earlier in the Crimean Sea. In addition, Russia is working on the air-independent propulsion unit on the order of the Foundation for Advanced Research.

    The unmanned underwater vehicle Sarma, developed by the Lazurit design bureau, will be able to dive to a depth of 1 km. Similarly, the vehicle will carry out assigned missions autonomously for three months. The submersible will be able to cover a distance of more than 8,000 km. The Sarma can perform a range of tasks, including bottom survey, bottom topography, monitoring of long objects (gas pipelines), mapping, geological exploration, and maintenance and repair of underwater communications in the oil and gas sector. “Maintenance of under-ice monitoring and lighting systems” is also among the potential tasks of drones (source).

    4.3. China

    The Chinese People’s Liberation Army (PLA) Navy has a project dubbed the “Great Undersea Wall” (source). Intended to protect the South China Sea from underwater incursions, the Great Undersea Wall is similar to the Acoustic Surveillance System (SOSUS). SOSUS is a network of seabed hydrophone arrays built by the US to detect and monitor Soviet submarines during the Cold War. It consists of active and passive sensors, UUVs, and manned submersibles.

    Beyond the three major Chinese AUV design centres, a growing number of research institutes and private companies are entering the Chinese AUV market. As of 2019, China hosts 159 AUV research projects at more than 40 Chinese universities. This is a significant increase from the 15 major universities that had built AUV research teams four years earlier.

    In September 2021, Chinese researchers tested a new underwater drone in what appears to be its first open-water test. This holds significant implications for geopolitical stability, as the tests took place in the South China Sea. A university with close ties to the Chinese military created the drone using a bio-inspired design. The drone uses the shape of a manta ray to help it glide efficiently through the water (source).

    4.4. France

    France intends to develop collaborative combat in order to free itself from environments and to combine the effects of armies (multi-domain concept) with hyperconnectivity, which represents a real technological challenge for underwater vectors (source). To deal with the difficulties of underwater communication, research and development work is suggesting interesting avenues. However, no satisfactory solution has yet emerged.

    4.5 The UK

    The UK Submarine Delivery Agency’s Autonomy Unit has launched a tender worth up to £21.5 million for the procurement and testing of an 8-12 metre Extra Large Autonomous Underwater Vehicle (XL-AUV), known as the CETUS project.

    The CETUS project involves the design and construction of a ‘very large autonomous underwater vehicle’ that could one day work alongside the British attack submarines. The resulting XL-AUV will help the UK Navy reduce the risks associated with the acquisition of future UUVs.

    The UK Navy already has an Extra Large Unmanned Underwater Vehicle (XLUUV) which they use to test various payloads. The Project CETUS work follows on from XLUUV experimentation and will be the service’s first purpose-built XL-AUV. Design work should be completed in 2022-23, with the delivery of the demonstrator to follow in 2023-24.

    The Office of Naval Research undertaking Autonomous Underwater Vehicle Testing
    Img; The Office of Naval Research undertaking Autonomous Underwater Vehicle Testing; via the Office of Naval Research on Flickr

    5.0. What are the Limits of UUVs?

    While UUVs are a valuable addition to naval and submarine fleets, there are limitations to underwater communications. Military organisations must look at how to overcome such limitations for the persistent missions the military wishes to accomplish. The main problem with UUVs is communication. The only communication with these vehicles is snippets of information that come back acoustically. The vehicles are unable to send back any data unless they surface to do so.

    To address the challenges of underwater communications, solutions are being explored such as small software-defined radio systems, advanced acoustic detection and communication systems, and artificial intelligence and machine learning. It’s not just about putting UUVs in the water, it’s about getting the “right data to the right decision-makers, in the right format” (source). Ultimately, this would mean that UUVs could facilitate decisions and provide states with a tactical advantage. However, there are some solution like ULTRA that offers wireless communication underwater using lasers.

    AUVs generally operate in a set pattern to map a large area of the ocean. Artificial intelligence could allow AUVs to make decisions, modify their trajectory, and even decide whether to take offensive action.

    6.0. The Role of Artificial Intelligence…

    The difficulties of underwater communication thus make the autonomy of UUVs all the more necessary. They need to be able to make decisions, and that’s where AI comes in. It is a matter of equipping the vehicles with AI and machine learning for automatic target recognition. The concept is to teach the AUV what a mine looks like, for example. So if it detects one it tags it, comes to the surface, quickly offloads the images and continues on its mission (source).

    Thanks to AI, AUVs will be able to go beyond missions that require them to follow a predefined trajectory, moving from one landmark to another. With AI, the aim is to maximise the search parameters to identify objects of interest. The UUVs will be empowered to make decisions and share information with other resources, in a logic of interoperability and connected warfare.

    A vehicle equipped with a sophisticated side-scanning system, for example:

    1. Could search for and locate a mine;
    2. then call a vehicle equipped with a high-quality camera nearby to get a better view;
    3. all without human intervention.

    The AUV will also be able to select the data of interest to avoid overwhelming the operator.

    Finally, from a military perspective, vehicles will have to go much deeper and stay longer for missions. This is because the missions require:

    • High survivability
    • Higher energy density
    • Greater degree of autonomy

    This will require the use of Artificial Intelligence.

    Eventually, as autonomy improves, AUVs will operate in swarms. They will also communicate and solve problems with other AUVs, USVs (unmanned surface vehicles) and aerial drones (source).


    Therefore, the seabed offers a myriad of opportunities for states and is a highly strategic area of operation.  As such, major powers have vested interest in equipping themselves with Unmanned Underwater Vehicles and preparing for underwater warfare. In the future, artificial intelligence will enable UUVs to carry out ever longer missions and to learn about connected warfare.

    Hugo Patin
    Hugo Patin
    Hugo holds a Master's degree in economic and social studies from the University of Paris 1 Panthéon Sorbonne. He is currently an international volunteer for France in Senegal, West Africa. Passionate about geopolitical issues, he has developed a strong interest in the analysis of defence issues.

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