Unmanned underwater vehicles (UUV), also known as underwater drones, or unmanned submarines, are submersible vehicles that can operate underwater without a human occupant, either remotely operated underwater vehicles (ROUVs) or autonomous underwater vehicles (AUVs).
Classifications
Remotely operated underwater vehicle Remotely operated underwater vehicles (ROUVs) primarily replace humans in difficult underwater conditions and perform educational or industrial missions. They are manually controlled to perform tasks that include surveillance and patrolling. ROUVs cannot operate autonomously. In addition to a camera, actuators, and sensors, ROUVs often include a 'gripper' or something to grasp objects with. This may throw off the weight distribution of the vehicle, requiring manual assistance at all times. Sometimes ROUVs require additional assistance due to the importance of the task being performed. The US Navy developed a Submarine Rescue Diving Recompression System (SRDRS) that can save up to 16 people up to 2000 feet underwater at a time. Such a large vehicle with the primary role of saving lives requires an operator(s).
Autonomous underwater vehicle Autonomous underwater vehicles (AUVs) are underwater vehicles that can operate without an operator. Sizes can range from just a few kilograms up to thousands of kilograms. The first AUV was created in 1957 to perform research in arctic waters for the Applied Physics Laboratory at the University of Washington. By the early 2000s, 10 different AUVs had been developed, including screw driven AUVs, underwater gliders, and Bionic AUVs. The earliest models used screw propeller thrusters while more recent models use automatic buoyancy control. The earliest model, SPURV, weighed 484 kg, went as deep as 3650 meters, and could travel for up to 5.5 hours. One of the most recent models, Deepglider, weighs 62 kg, can go as deep as 6000 meters, and can travel up to 8500 km.
History
1950s Starting in 1957, the first uncrewed underwater vehicle (UUV) was classified as an autonomous underwater vehicle (AUV), and was created in the United States to research the Arctic waters. The Special Purpose Underwater Research Vehicle (SPURV), was used by the University of Washington to collect oceanographic data until 1979 during which the development of SPURV II began to provide better movement performance and better sensing capabilities.
1970s Scientists from the Autonomous and Control Processes Institute took interest in the developments of the AUV “SCAT” which led to the introduction of the UUVs “L1” and “L2” in 1974. “L1” and “L2” are AUV models used for the further development of technology and oceanographic mapping respectively.
1980s Further development of the Remotely operated Vehicle (ROV) brought forth the creation of the Autonomous and Remote controlled submarine (ARCS) in 1983 by the ISE ltd. company in partnership with the “International Submarine Engineering”. ARCS was also classified as a Remotely controlled underwater vehicle (ROUV) because of its 32-bit Motorola processor which allowed for the remote control it featured. This UUV further served as a testing platform, improving on the battery life, navigational, and communicational systems having its first dive in 1987.
1990s When the Russian Institute of Marine Technology Problems introduced the Solar Autonomous underwater vehicle (SAUV), it was the start of longer term exploration missions without the need of retrieving the UUV for maintenance. The introduction of solar panels on UUVs began with the SAUV in 1987 and was kept during the making of SAUV II. Solar panels enabled lengthier missions, with the ability to use features such as gps and high payloads more frequently due to its ease of charge.
Advancements in battery life enabled for the creation of “gliders” in 1995 which would allow for the long term dives in which the UUVs would remain submerged for weeks or even months at a time.
2000s UUVs begin to be taken into consideration for more than testing tools for other underwater missions due to the increase number of user internationally. There was also an increase in funding for the UUV technology development. The rise in users internationally led to the increase demand for UUV technology outside of government agencies and the commercial sale of UUVs started, expanding the research based use of the UUV to a more industrial/commercial based use.
2016 incident
On December 16, 2016, a Chinese warship in South China Sea seized an underwater drone that was in the process of being retrieved by the U.S. Navy survey ship USNS Bowditch. A day later, the Chinese Defense Ministry said it will return the drone to the United States. The Pentagon confirmed that and says the drone, used for gathering weather and temperature data, is not armed. The drone was returned several days later.
2020s
In early 2023, following successful military use of uncrewed surface vehicles (USV) by Ukraine in the Black Sea in October and November 2022, the Ukrainian Navy began to employ an uncrewed underwater vehicle (UUV), a maritime drone, called the Toloka TLK-150. A small robotic submarine, the TLK-150 is long, with twin thrusters mounted on wing-like stabilizers. Although "smaller than previous Ukrainian maritime drones [and with a] much shorter range and slower speed, [it] should make up for that by being more stealthy and more survivable. An advanced version has a range of 2000 kilometres and a payload approaching 5000 kg of explosives and has been effective in destroying vessels and infrastructure such as the Kerch Bridge.
TLK-150 is developed by Brave1, which has designs for two larger UUVs. The TLK-400 is longer at and "has a much larger diameter body inferring greater range and payload. The TLK-1000 would be much larger again, up to 12 meters (40 feet) in length and with four thrusters."
In April 2024, Ukraine has announced that it was testing an “uncrewed submarine” that can be fitted with a warhead, stealth features and sensors, carry up to 10 divers, carry six torpedoes or missiles and has an endurance of 54 hours/1000 kms, with a speed of up to 50 kms/h underwater.
In May 2024, Northrop Grumman unveiled an underwater drone named the Manta Ray, developed for the Defense Advanced Research Projects Agency (DARPA). Modeled after the manta ray, this drone underwent four years of development to mimic the movements of this oceanic creature. The product is engineered for extended-duration and long-range military operations with minimal human intervention. Additionally, it features the capability to harness energy from the ocean. Manta Ray successfully completed full-scale at-sea trials off the coast of Southern California in February and March 2024. According to DARPA, Manta Ray demonstrates a first-of-its-kind capability for an extra-large UUV due to its "cross-country modular transportation, in-field assembly, and subsequent deployment."
In April 2025, Anduril Industries announced their Copperhead (UUV) family of autonomous unmanned underwater vehicles, which includes a loitering munition.
In December 2025, Ukraine claimed that it conducted a military operation that struck a Russian submarine with underwater drones. The SBU said that the operation was the first of its kind. The submarine was struck in the port of Novorossiysk, a heavliy protected port.
Design Gliders External fins perpendicular to the frame of the UUV which allowed for a linear movement of the UUV and deeper, controlled dives. These gliders use buoyancy derived propulsion which increases the duration of dives and their range through up and down movement in the ocean.
Manta ray In September 2021, researchers at a Chinese university developed a manta ray shaped UUV with the purpose of collecting information around the Paracel Islands. Some UUVs are designed to mimic the silhouettes of animals to facilitate movement and prevent detection. The manta ray design allows the UUV to camouflage with the marine life and contributes to the ease at which the craft swims through water.
In May 2024, Northrop Grumman revealed an underwater drone named the Manta Ray. The drone, built for DARPA, has been under development since 2020. The Manta Ray, along with the Orca developed by Boeing, represents a new class of uncrewed underwater vehicles (UUVs), that were developed to perform long duration, long range military missions with as little human oversight as possible. The Manta Ray is also capable of harvesting energy from the ocean.
Oxygen/hydrogen air-independent propulsion UUVs with combustion engines are oxygen dependent vehicles which require to resurface. With the development of a propulsion unit that does not require oxygen or hydrogen, the ability for the UUV to stay continuously underwater increases drastically.
Applications
Military The US Navy began using UUVs in the 1990s to detect and disable underwater mines. UUVs were used by the US Navy during the Iraq War in the 2010s to remove mines around Umm Qasr, a port in southern Iraq.
The Chinese military uses UUVs for mostly data collection and reconnaissance purposes. In May 14, 2025 the NavalNews website published a candid photograph of a likely extra-large uncrewed underwater vehicle being transported under wraps with the speculation that it was the armed UUV-300 design which can host torpedoes, missiles, and mines. The British Royal Navy's Project Cetus vehicle and the Canadian's Cellula Robotics Solus-XR are of similar size.
On December 20, 2020, a fisherman in Indonesia spotted a glider-shaped UUV near Selayar Island in South Sulawesi. Individuals from the Indonesian military have categorized the vehicle to be a Chinese Sea Wing (Haiyi), created for the purposes of collecting data including water temperature, salinity, turbidity, and oxygen levels that can help chart optimal submarine routes.
The navies of multiple countries are developing sophisticated Large unmanned undersea vehicle also known as LUUV or XLUUV, the definition of a LUUV usually involves it being greater then 10 m (32 ft 10 in) in length. Notabul XLUUV's include the US Navy's Orca (AUV) at 85 feet (26 m) development starting in 2017. The United Kingdom has developed Project Cetus a XLUUV at 12 m and with up to 25 tonnes Displacement. There is a further joint venture between US and Australian Navy called Ghost Shark (submarine) this XLUUV also at 12 m with a displacment of 10 tones.
Governments including the US, UK, France, India, Russia, and China are currently creating uncrewed vehicles to be used in oceanic warfare to discover and terminate underwater mines. For instance, the REMUS is a three-foot long robot used to clear mines in one square mile within 16 hours. This is much more efficient, as a team of human divers would need upwards of 21 days to perform the same task.
A survey conducted by RAND Corporation for the US military analyzed the missions which uncrewed underwater vehicles could perform, which included intelligence, reconnaissance, mine countermeasures, and submarine warfare. The review listed these from most to least important.
In November 2022, the Eurasian Times reported that China's Harbin Engineering University has developed trans-medium 'flying submarine' drones capable of both underwater and air travel, noting the potential military applications of the vehicles.
In August 2026, US officials with firsthand knowledge corroborated US President Donald Trump's assertion during the 2026 Iran war that the US Navy had cleared mines from the Strait of Hormuz's Traffic Separation Scheme, Oman's primary maritime corridor with Iran, adding that over the last few months, underwater drones carried out a systematic scanning of the area, identifying over 100 objects suspected of having mines, which were then removed or detonated by private contractors.
Status-6 Oceanic Multipurpose System