China Gives Drone Back—But Why Did They Grab It In The First Place?

Last Thursday the USNS Bowditch (T-AGS-62), a non-combatant US naval research vessel, was recovering two low-buoyancy underwater gliders while the Chinese Dalang III class rescue and salvage ship Nan-Jiu was shadowing them. Crew from the Nan-Jiu launched a small boat, sped up to one of the little drones and plucked one out of the water. The Bowditch’s crew watched the abduction go down in plain sight. The incident occurred about 50 miles west of the Philippines in the tense waters of the South China Sea.

The official statement from the Pentagon made last Friday following the incident reads:

“Using appropriate government-to-government channels, the Department of Defense has called upon China to immediately return an unmanned underwater vehicle (UUV) that China unlawfully seized on Dec. 15 in the South China Sea while it was being recovered by a U.S. Navy oceanographic survey ship. The USNS Bowditch (T-AGS 62) and the UUV — an unclassified “ocean glider” system used around the world to gather military oceanographic data such as salinity, water temperature, and sound speed – were conducting routine operations in accordance with international law about 50 nautical miles northwest of Subic Bay, Philippines, when a Chinese Navy PRC DALANG III-Class ship (ASR-510) launched a small boat and retrieved the UUV. Bowditch made contact with the PRC Navy ship via bridge-to-bridge radio to request the return of the UUV. The radio contact was acknowledged by the PRC Navy ship, but the request was ignored.  The UUV is a sovereign immune vessel of the United States. We call upon China to return our UUV immediately, and to comply with all of its obligations under international law.”

The ocean research vessel USNS Bowditch. , USN

These little (about six feet in length) reconfigurable drones are not classified technology, far from it in fact. They serve with government agencies and universities around the globe and are not super high-tech as far as unmanned underwater vehicles go by any means.

Gliders like Teledyne Marine’s Slocom—which is what the Navy’s Littoral Battlespace Sensing-Glider (LBS-G) is based on—move through the water without traditional propulsion. Instead, they utilize shifting internal ballast, along with their wings to provide lift, porpoising up and down through the depths. They are semi-autonomous and can carry various payloads both internally and externally. Persistence is one of their great advantages as they can stay active in an area for months at a time while being monitored and controlled by small teams using desktop computer interfaces and commercial communications satellites or line-of-sight data-links 

Defense Industry Daily describes how the Slocom works:

“Teledyne’s glider uses changes in buoyancy to propel itself through the ocean. Instead of using mechanical means to change that buoyancy, however, it mostly relies on the ocean’s own temperature and pressure changes.

To sink, a valve allows oil from a flexible bladder on the outside to flow in, lowering volume but keeping mass constant. The glider sinks. Liquid wax inside internal tubes shrinks and solidifies as it descends into colder waters, letting oil in. The glider will continue descending to about 5,000 feet, then another internal storage tank filled with oil and nitrogen at 3,000 psi pressure is used to force oil back into the external bladder. As the now-buoyant glider heads toward the surface, its wings provide lift and forward motion, while sensors in the nose gather oceanographic data.

The glider will eventually surface about 5 km/ 2.75 miles away, where surface water temperatures of about 80F/ 27C liquefy the wax again. Liquids can’t really be compressed, so the liquid wax forces the oil and nitrogen back into the storage tank, resetting the gas “spring” for use in the next cycle. At the surface, the glider reports its position, transmits data via satellite, and receives any sent commands.

That propulsion system means the glider can be at sea for weeks at a time, allowing subsurface sampling on a regional scale. In 2009, a Slocum Glider managed to cross the Atlantic in 223 days”

Technicians work on a Slocum glider used by the US Navy., USN

Underwater gliders are used primarily for oceanic research, such as mapping water temperatures, listening for marine life, measuring depths, currents, salinity and the like. That’s not to say that the scientific products they create aren’t used to aid in submarine, anti-submarine, amphibious or irregular warfare operations. Just knowing what these variables are at any given time can greatly enhance the effectiveness of a nearby ship or submarine’s sonar. It also doesn’t take much imagination to realize that similar systems could be used to do things like listen for submarines and record the audio signatures of different vessels within a specific geographical area.

A slide detailing the Littoral Battlefield Surveillance Glider program, DoD

The truth is, China has a history with being very curious—even outright suspicious—of these types of strange underwater vehicles that have popped up from time to time. In 2015 I broke the story in the US about a puzzling cylindrical mechanized contraption hauled up by a Chinese fisherman in a very sensitive maritime area. It made major news in China and seemed to spook the Chinese military significantly.

With this in mind, being able to pluck anything similar out of the water from a known source probably is a pretty high-priority act for the PLAN. Especially if said thing was being deployed in highly disputed waters where you are massively invested militarily. Now doing so right in front of the crew that launched it is tacky and may have violated international maritime law, but then again it’s the South China Sea, a place where China has totally blown off the will of international governing bodies.  

On Saturday, China’s Foreign Ministry Spokesperson Hua Chunying said the following about the incident:

“An unidentified device was discovered by a lifeboat of the Chinese Navy in waters of the South China Sea. In order to prevent this device from posing danger to the safe navigation of passing ships and personnel, the Chinese side checked and verified the device in a professional and responsible attitude. After identifying the device as a UUV from the US, the Chinese side decided to hand it over to the US side in an appropriate manner. It is learnt that the two sides are in smooth communication through the military-to-military channel, which will definitely lead to a proper settlement of this issue.”

China also noted how the American media was playing up the incident, saying that “The U.S. side’s unilateral move to dramatize the issue in the process is inappropriate, and not conductive to its settlement.” It is true, the story dominated headlines on Friday and throughout the weekend, with loads of inaccurate information and hyperbole being delved out by major outlets. President-elect Trump even commented on it, not once but twice:

Trump’s first tweet was inaccurate, as China had not taken the drone back to the mainland. Trump’s second tweet on Saturday held a very different tone:

Although this all may have been somewhat unprecedented, it’s not like this is the first time American military hardware operating in international territory has fallen into Chinese hands. The snatching of maritime drones will become a common occurrence in the decades to come as the world’s seas become increasingly populated by unmanned systems. It should serve as a case study for emerging unmanned surface vehicle initiatives, especially far more complex and sensitive ones like DAPRA’s ACTUV.

Now, a few days after being taken and just as China promised, the drone has been returned to the US Navy. The Arleigh Burke class destroyer USS Mustin rendezvoused with the same Chinese salvage and rescue vessel that grabbed the drone on Friday and it was peacefully handed over. The DoD says that they will continue to investigate the incident and will take further diplomatic actions if necessary, although that won’t likely happen. It remains unclear if the ocean glider was manipulated in any way while aboard the Chinese vessel, but it should be safe to assume that it was. Regardless, you can be pretty certain the US Navy will be extra careful when it comes to choosing which computer they will plug into the glider’s brains now that it’s back in their custody.

So why did China snatch the drone in the first place? Some say they wanted to send a message to President-elect Trump, following his comments on Taiwan. Although this could have been a factor, I doubt it was the primary reasoning behind the operation. It’s more likely that China is very suspicious of these vehicles and wanted to check out a functioning specimen in the configuration being used by the US Navy in that highly contested area of the world. When the right opportunity presented itself, they did just that.

Finding out exactly what the payloads on these devices are capable of would be highly valuable intelligence for the PLAN. And let’s face it, nobody is going to go to war over losing one of these drones for a few days. The US didn’t even act kinetically when a highly classified unmanned stealth flying wing, the RQ-170 Sentinel, dropped into Iranian hands in late 2011. Nor did they bomb the intact tail of the even more classified stealth Black Hawk helicopter that landed on the wrong side of Osama Bin Laden’s compound wall in Pakistan out of fear of killing civilians. The Chinese know this all too well, and factor in historical reactions carefully when making a play like this. The fact that the USNS Bowditch is an unarmed deployment vessel for the gliders made them an especially ripe target for the picking.

The Teledyne Slocum G2 seen underwater., Teledyne

As for the US Navy using these simple unmanned underwater vehicles in a direct military role, well, they’ve been launching them from submerged nuclear submarines for over a decade and are now deploying them from destroyers as well. If these quiet, ultra-long endurance gliders can acoustically detect schools of fish and whales in a high-fidelity acoustic manner, they are also likely able to detect naval assets—including submarines prowling far below the surface.

The best part about using commercially available hardware like this is that high-tech classified gear doesn’t have to be put at risk of capture. As such, they represent an inherently low-risk and high reward proposition. In fact, when it comes to military hardware, these drones aren’t even that expensive—costing less than a couple hundred thousands dollars each. And yes, mapping the movements of Chinese submarines 50 miles off Subic Bay in the South China Sea would represent very valuable data, even if it was “inadvertently gained” by an underwater glider while on a “scientific mission.”

On a larger scale, deploying small groups of these gliders to strategic maritime choke points, including those in the South China Sea, could provide the Navy with very cost effective, persistent and low risk intelligence on the comings and goings of local sea traffic—even on the type that operates deep below the surface and under thermocline layers. Think of it as a more adaptable, focused, less expensive, and highly deployable mini-SOSUS network. Whether or not this is actually being done, and by what underwater vehicles and on what scale remains unclear, but wouldn’t the Navy be stupid not to employ such a strategy? Still, even just having these gliders execute their disclosed mission they are improving US Navy capabilities—especially their sonar sensing abilities—in the region.

So yeah, if you were Chinese, you would be very suspicious of these things too, although that still doesn’t justify the act.

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