Indonesia and China are at maritime loggerheads amid rising Chinese incursions into Indonesia's exclusive economic zone. Image: Twitter

JAKARTA – Indonesia’s interception this week of a Chinese research ship, which had crossed the Java Sea without an activated transponder, and last month’s discovery of a suspected Sea Wing underwater drone off southern Sulawesi has presented Jakarta with a new set of issues in its uneasy relations with Beijing over maritime sovereignty.

On the evening Chinese Foreign Minister Wang Yi concluded an official visit to Jakarta, an Indonesian Coast Guard patrol ship shadowed the survey vessel Xiang Yang Hong 03 into the strategic Sunda Strait separating Java and Sumatra after it turned off its automated identification system (AIS) three times between January 8 and 12. 

Under provisions in the United Nations Convention on Law of the Sea (UNCLOS) recognized by most countries, Indonesia requires all ships transiting the world’s only archipelagic sea lanes to have functioning AIS and forbids them from carrying out oceanographic research.

In addition, foreign warships are permitted to conduct limited flight operations and submarines can remain submerged as long as they don’t stray more than 25 nautical miles on either side of their charted course through the three designated north-south lanes.

The Maritime Security Agency (BAKAMLA) said the Xiang Yang Hong 03 killed its transponder twice while passing through the Natuna islands at the southern end of the South China Sea and later in the Karimata Strait, northeast of the island of Belitung.

The Indonesian patrol craft KN Nipah Island did not attempt to close with and board the Chinese vessel because of bad weather, but they were told by radio that the AIS had been damaged. It was later escorted out of Indonesia’s Economic Exclusion Zone (EEZ).

The Xiang Yang Hong 03 survey vessel in a file photo. Photo: Facebook

The incident came only a fortnight after Indonesia announced the discovery of a so-called Sea Glider off South Sulawesi’s Selayar Island. Carrying a trailing antenna and with no identifying marks, it was the third found in Indonesian waters in the past year, although the previous finds were not made public.

One of the drones was recovered in the Natuna islands in March last year. Earlier this month another was found by fishermen north of the East Java port city of Surabaya near the approaches to the Lombok Strait separating Java and Bali.

“As Chinese naval activity through the Western Pacific and out into the Indian Ocean continues to grow, it seems likely that these kinds of finds will become more and more common,” says one naval analyst who tracks Chinese ship movements in the region.

In 2017, the Chinese government was reported to be testing how glider-type drones, thought to be versions of the Sea Wing, could act as communications and data-relay nodes to help rapidly transmit information useful for detecting and tracking foreign submarines.

As with incursions by heavily-armed Chinese Coastguard vessels into Indonesia’s 200-nautical mile EEZ around the Natuna archipelago, Indonesia’s government has been reluctant to stir up a dispute with Beijing over the covert undersea research.

Because the ownership of the drones can’t be proven, Indonesian Foreign Minister Retno Marsudi apparently felt justified in not raising the issue with her counterpart Wang during this week’s visit. Instead, she reportedly did discuss the ill-treatment of Indonesian crewmen aboard Chinese trawlers.

“The more the Indonesians complain, the more it seems to China that they are swinging towards the US,” says one regional analyst. “They are caught between remonstrating with China or just doing nothing and letting them get away with it.”

Over the past two years, President Joko Widodo’s government has taken pains to reinforce an independent foreign policy that steers a careful course between the two superpowers to avoid being dragged into their growing rivalry.

Indonesian President Joko Widodo aboard a naval vessel in a file photo. Photo: Twitter/Presidential Handout

In her year-end statement, Marsudi pointedly quoted Indonesia’s founding father Mohammad Hatta: “We must not become the object of an international conflict. On the contrary, we must remain the subject who reserves the right to decide our own destiny.”

Still, without mentioning China, the minister did underscore the importance Indonesia attaches to its maritime sovereignty, one issue that brings Indonesian nationalism to the fore and which no Jakarta government can afford to ignore.

The Foreign Ministry recently sent to the United Nations a claim for the extension of its continental shelf southwest from the island of Sumatra and beyond the prescribed limits of the Indian Ocean EEZ, something it is entitled to do if there is no common border.

That and earlier efforts to expand the continental shelf off northern Papua and in other areas of the archipelago and to improve inter-connectivity between the islands are part of Widodo’s grand strategy to transform Indonesia into a maritime power.

Produced and operated by the state-run Chinese Academy of Sciences’ Shenyang Institute of Automation since 2014, the Sea Wing drones can remain at sea for more than a month and reportedly have the ability to operate at extreme depths.

The Chinese research ship Xiang Yang Hong 06 deployed at least 12 of the drones in the eastern Indian Ocean in late 2019, later claiming that they traveled a collective 12,000-kilometers in a comprehensive search for hydrological data.

Analysts believe the Chinese cloned some of the features for the newly-upgraded Sea Wing from an American sea glider, snatched from under the nose of the US Navy in the South China Sea in December 2016 and only returned months later after a diplomatic spat.

China’s Sea Wing underwater drone. Image: www.navaldrones.com

Publicly, the torpedo-shaped, 2.2 meter-long Sea Wing is used purely for oceanographic research, taking sonar soundings of the ocean floor and measuring the strength and direction of currents, water temperatures, salinity, turbidity and oxygen levels.

But experts say that same data can also be used to support future naval operations, analysts say. “Accurate maps and charts for critical waterways will be ever more important for both day-to-day activities and any actual future combat operations,” says the naval analyst.

Aside from detailed mapping of the contours of the seabed, research into the propagation of sound underwater paints a picture of the acoustic and thermal environment, allowing submarines to hide under layers of thermocline to avoid sonar detection from surface warships.

“These discoveries in Indonesian waters suggest we should be paying a lot more attention to what the Chinese are doing and why,” says Australian Strategic Policy Institute (ASPI) analyst Malcolm Davis, referring to China’s plan for an “Underwater Great Wall” project announced in 2017.

Davis and other naval observers conclude that China intends to build a network of sensors and platforms that will give them a better “situational awareness” of the Indian Ocean, specifically the movements of American submarines.

The US Navy submarine tender USS Emory S Land is permanently stationed at Diego Garcia, an island base in the mid-Indian Ocean, in addition to pre-positioned ships providing logistical support to operational forces in the wider region.

Jane’s Defence Weekly reports that the China State Shipbuilding Corporation has furnished blueprints of the planned network to the People’s Liberation Army Navy (PLAN), which currently lists 79 submarines in its inventory, including six nuclear-powered craft. 

With 45% of its oil imports sourced from the Middle East, China is building up a significant fleet in the Indian Ocean, beginning with its first long-range deployment of warships to join an anti-piracy task force in the Gulf of Aden in 2008.

The Middle East and Africa are also an integral part of China’s Belt and Road initiative, with President Xi Jinping visiting the region 18 times since coming to power eight years ago.

Employing variable buoyancy propulsion, sea gliders are pre-cursers to a new generation of armed Unmanned Underwater Vehicles (UUV), capable of operating in the shallow waters of the Sunda and Malacca straits, conduits for the vast majority of commercial shipping.

Map: US EIA

China recently launched the twin-prop HSU-001, a large, unmanned drone similar to the US Navy’s Orca, which is capable of operating far from home on missions to gather intelligence, lay or clear mines and attack other ships or submarines.

Manned underwater craft, particularly US Navy nuclear submarines, mostly use the Lombok and easternmost Ombai straits, ranging in depth from 1,400 to 3,200 meters, to transit from the South China Sea and the Pacific Ocean into the Indian Ocean.

Analysts say the Chinese research ships commonly traverse the broad Makassar Strait, between the islands of Kalimantan and Sulawesi, before heading into the Banda Sea and out into either the Indian Ocean or the Western Pacific.

It is not clear what vessel is suspected of deploying the Sulawesi drone, but trackers say the Xiang Yang Hong 06 left its home port of Qingdao, north of Shanghai, on December 11 and switched off its AIS on December 18, north of the Sulu Sea in the Philippines.

Where it went after that is guesswork. A week later, on December 26, the Xiang Yang Hong 06 re-activated its transponder, giving it enough time to have passed through the Molucca Sea between Sulawesi and Halmahera and then back into international waters north of Papua New Guinea.

Its sister ship, the Xiang Yang Hong 01, left Qingdao on December 18 and it too switched off its responder as it neared the Indonesian EEZ. It returned to screens a week later as it entered the Sunda Strait on what appeared to be an uninterrupted passage into the Indian Ocean, where it continues to operate.

Indonesia established its north-south sea-lanes in late 2002, a decade after the United Nations Convention on Law of the Sea (UNCLOS) formally recognized the existence of archipelagic states, with the legal authority to claim sovereignty over their internal waters.

An Indonesian officer on guard in front of a naval vessel in a file photo. Photo: Twitter

At an International Maritime Organisation (IMO) conference the following year, Indonesia indicated it might agree to an east-west lane, a proposal pushed by the now-renamed United States Indo-Pacific Command in particular.

Later in 2003, Indonesia scrambled F-16 fighters from their East Java base to intercept a flight of five F-18 jets launched from the US aircraft carrier Carl Vinson as its battle group headed through the Java Sea towards the Lombok Strait.

The Carl Vinson was still 300 kilometers away from the north-south lane stretching between the Makassar and Lombok straits when it began what was seen as a test of Indonesia’s recognition of the east-west passage, a practice that persisted up until 2016.

The IMO continues to call the three sea-lanes “partial ASLs” until such time that Indonesia establishes an east-west corridor, but Arief Havas Oegroseno, the former deputy for maritime sovereignty in the Maritime Affairs Ministry and currently ambassador to Germany, argues that Jakarta is under no obligation to do so under the convention.

Oegroseno points to Article 53 (1) of the convention, which states: “An archipelagic state may designate sea lanes and air routes there above, suitable for the continuous and expeditious passage of foreign ships and aircraft through or over its archipelagic waters and the adjacent territorial sea.”

Interestingly, the US Department of Defense did not include Indonesia in its latest freedom of navigation report identifying what it considered to be the excessive maritime claims the US had operationally challenged over the previous year.

What happened? “China happened,” says the naval analyst. “The US Navy’s priorities have changed.”