The Indian Ocean features numerous trade routes, is ringed by naval bases, and is the stage for many maritime operations and exercises involving assets from a range of nations. Unsurprisingly, therefore, this ocean is a focus for China, as it seeks to become the world's leading maritime power.
The Chinese People's Liberation Army Navy (PLA-N) has had a significant presence in the Indian Ocean since 2009, with its warships carrying out anti-piracy and anti-terrorism operations, sometimes as units of multi-national task groups.
A key node of the Chinese push to dominate the Indian Ocean is the PLA-N base at Djibouti. This facility has been upgraded with a 300-metre jetty, and according to recent reports, underground electronic warfare and cyber security facilities have also been installed. China also now has access to ports at Gwadar in Pakistan, Hambantota in Sri Lanka, and, furthermore, is eyeing the setting up of naval support facilities in Tanzania and Mozambique.
PLA-N submarines have been active in the Indian Ocean since at least 2013. Initial forays were by Yuan-class diesel-electric attack submarines. Shang-class nuclear-powered boats began deploying to the Ocean in 2015. Both classes of submarines operate from Sanya base on Hainan Island and are often accompanied by PLA-N support vessels.
Other types of Chinese auxiliary vessels have also established a presence in the Indian Ocean in order to help sustain the PLA-N's underwater operations. These include ocean survey vessels that have been using side scan sonar to chart a number of areas, including routes vital to submarine deployments into the Indian Ocean via the Malacca, Lombok and Sunda Straits. These vessels also operate uncrewed underwater vehicles, including wave gliders, to record measurements of the seabed.
The activities of these specialist vessels have attracted the attention of major regional maritime players, particularly India. Also being carefully watched by the Indian Navy are the PLA-N satellite and ballistic missile tracking ships Yuan Wang 5 and Yuan Wang 6. These vessels likely operate with Chinese submarines in monitoring Indian and allied naval activity.
In October of this year, the presence of Yuan Wang 6, which has recently been operating out of Hambantota, caused the test firing of a K-15 ballistic missile from the Indian Navy's nuclear-powered submarine Arihant to be delayed.
Analysts believe Beijing is using the operations of its submarines and specialist surface vessels to help calculate strategies for possible future undersea warfare in the Indian Ocean. To this end, its submarines track US and allied submarines and surface warships to ascertain their operational pattern, sound signatures, and capabilities. Its survey vessels meanwhile provide the data to enable PLA analysts to calculate optimum areas for safe and effective navigation of submarines.
Another aspect of China's efforts to influence the Ocean's prospective underwater warfare scenario is the provision of diesel-electric attack submarines to Pakistan. Bangladesh, Myanmar, and Thailand. Bangladesh and Myanmar have been provided with ageing former PLA boats with limited capabilities.
Thailand, however, is due to receive a new-build S26T boat, based on the PLA-N's Yuan-class submarines, Also based on the Yuan-class are eight new Hangor-class submarines featuring air-independent propulsion, to be supplied to Pakistan. Three are reportedly to be delivered in the near future, with production being split between yards in Wuhan in China and Karachi in Pakistan.
According to some reports, the Thai and Pakistani projects have both been hampered by engine supply difficulties, as plans to use engines manufactured by UK-owned, Germany-based MTU have been scuppered by EU sanctions.
In response to Beijing's Indian Ocean moves, the "Quad" naval alliance (Australia, India, Japan, USA) has stepped up the frequency and intensity of its exercises. Also, of particular long-term significance is the AUKUS arrangement, under which the Royal Australian Navy (RAN) will eventually acquire and operate nuclear-powered attack submarines. The move has angered Beijing as it will dramatically increase the reach and potency of the RAN.
The induction into the RAN of either US- or UK- built nuclear-powered boats is still many years off, though operational training of RAN officers in US and UK boats has already commenced.
