Underwater drones are changing the complexion of maritime warfare. Image: Facebook

The drones that have changed the complexion of war from the sky are being replicated at sea, as great powers develop and deploy unmanned underwater vessels (UUVs) to gain a strategic edge in the Pacific and beyond.

The United States, United Kingdom, China and Russia are all developing and deploying the vessels, indicating the “dronification” of future maritime warfare.

The UK, which is expanding its military presence in the Pacific, is set to operate its first extra-large underwater drone to complement its Astute-class submarines. The Royal Navy’s efforts to design, build, and test such a drone have been designated Project CETUS, and aim to produce a 27-tonne, 12-meter Autonomous Underwater Vehicle (AUV) demonstrator.

The contract for Project CETUS is projected to be finalized in financial year 2021-2022, with a projected cost of 21.5 million pounds (US$29.3 million.)

The Royal Navy is also working on the Manta underwater drone, an unmanned version of the existing S201 manned submersible made by MSubs, a British manufacturer.

The US is working on the similar Orca Extra Large Unmanned Undersea Vehicle (XLUUV), as the US Navy awarded Boeing contracts worth a total of $274.4 million to produce five Orca XLUUVs in 2019.

The Orca can be used for mine countermeasures, anti-submarine warfare, anti-surface warfare, electronic warfare and strike missions without risking the lives of its operators.

China is also known to be using underwater drones, with Indonesia seizing three Chinese drones labeled “Shenyang Institute of Automation Chinese Academy of Sciences” near South Sulawesi’s Selayar Island in December 2020.

The same year, China allegedly deployed 12 Sea Glider underwater drones in the Indian Ocean to gather oceanographic data to support submarine operations.

China’s HSU001 unmanned underwater vehicle (UUV) is capable of launching a smaller underwater drone. Image: Getty via AFP

Moreover, China operates the HSU-001 underwater drone, which is roughly analogous to the Project CETUS, Manta, and Orca drones. The HSU-001 was reportedly tested off Fujian or the Taiwan Strait, simulating anti-submarine operations. 

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

The contested South China Sea is a semi-enclosed body of water with numerous unmapped underwater features and shallows, which makes navigation hazardous for both crewed surface and underwater combatants.

At the same time, the South China Sea provides an ideal operating environment for shallow-water conventional submarines, as the area’s underwater features and high shipping traffic enables such vessels to stay undetected for prolonged periods by using environmental factors to mask their signatures.

By extension, the South China Sea is an ideal proving ground for underwater drones, as they can perform underwater tasks that may be too dull, demanding, dangerous or even dirty for humans.

Underwater drones can be used for bathymetric mapping, alongside recording the thermal, magnetic, and acoustic properties of specific underwater passages to find blind spots where submarines can travel undetected safely.

As such, this capability is particularly suited for use in the South China Sea, which is among the most challenging bodies of water for submarine navigation due to its shallow waters, numerous underwater peaks and sandbars.

The recent collision of the USS Connecticut submarine with an unmapped seamount in the South China Sea illustrates the danger. In addition, these drones can also find submarine hiding spots to serve as staging areas for underwater operations, or sanctuaries to avoid enemy anti-submarine warfare operations.

The Seawolf-class fast-attack submarine USS Connecticut departs Puget Sound Naval Shipyard in Washington state for sea trials after maintenance in December 2016. Photo: US Navy / Thiep Van Nguyen II / Wikipedia

They can also potentially be used for mine-hunting and minelaying operations. Underwater drones can scout underwater minefields and possibly disarm naval mines. They may reduce, but not eliminate, the need for specialized diver teams to reconnoiter, identify, and demine potential landing beaches for amphibious warfare operations.

The drones can also perform anti-submarine operations by actively searching and tracking enemy submarines, without endangering manned surface vessels or submarines. The 1971 sinking of the Indian frigate INS Kukri by the Pakistani submarine PNS Hangor illustrates the possibility of anti-submarine warships becoming easy prey for enemy submarines.

The use of underwater drones for anti-submarine purposes will thus minimize the need to commit manned warships for such operations.

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

One such weapon is Russia’s Poseidon drone, which gives Russia a credible second-strike capability in the event of a nuclear attack.