In May this year, the INS Kalvari – the first of six French-built Scorpene-class submarines – was put to sea for the first time, marking the first step in the long journey to rebuild India’s depleted and creaking undersea fleet.

Diesel-electric submarines like these are typically quieter than their nuclear-powered counterparts, with particular advantages in shallow littoral waters – such as the waters off Pakistan’s port of Karachi or chokepoints like the Malacca Strait. 'The albacore shaped hull', boasted the Indian Express, 'is ideal for silent operations'. Television channel NDTV declared that 'they are so silent underwater that they are extremely difficult, if not impossible to detect'. France’s embassy in New Delhi hailed the boat as 'virtually undetectable'. 

But these acoustic advantages of the boat, along with others, might be somewhat blunted after a massive leak of technical data, running to over 22,000 pages, revealed by The Australian this week:

The leaked DCNS data details … what frequencies they gather intelligence at, what levels of noise they make at various speeds and their diving depths, range and endurance — all sensitive information that is highly classified. The data tells the submarine crew where on the boat they can speak safely to avoid ­detection by the enemy. It also discloses magnetic, electromagnetic and infra-red data as well as the specifications of the submarine’s torpedo launch system and the combat system. It details the speed and conditions needed for using the periscope, the noise specifications of the propeller and the radiated noise levels that occur when the submarine surfaces.

The newspaper noted that it had 'seen' – rather than 'obtained' – the documents, indicating that its access might have been limited. But this is little reassurance to the French or Indians. If The Australian’s investigative reporter is correct in asserting the raw data passed from French shipbuilder DCNS to companies in Southeast Asia and Australia, there can be little doubt that it is, or will soon be, in the hands of Chinese intelligence and, soon thereafter, Pakistan. Vice-Admiral A.K. Singh, a retired Indian submariner who served as head of the Eastern Naval Command, told The Wire that, in his view, 'this has saved the Chinese and Pakistanis 20-30 years of espionage'. This is a serious blow for New Delhi, but it also presents problems for Malaysia and Chile, which operate the Scorpene-class, Brazil, which will soon, and Australia, which chose DCNS over Japanese and German rivals to build its next generation of submarines.

Why have these document been leaked? After all, they have no public interest aspect whatsoever. The Australian reveals no design flaws, corruption, or other wrongdoing. Indian Defence Minister Manohar Parrikar has blamed 'hacking', and China has a long, successful, and well-known record of cyber-espionage in the defence sector. But it would be highly unusual for state actors to acquire and then publicise military secrets that could more usefully be kept private and exploited in wartime or to enhance intelligence collection at sea. DCNS itself has hinted, darkly, of corporate espionage – 'the competition is … hard and all means can be used' – and this certainly can’t be ruled out. France boosted its own measures against this activity in May, and both the German and Japanese intelligence agencies, among others, have in the past spied on private-sector targets, though almost always with the intention of aiding their national firms in private rather than the public revelation of information.

While the Scorpene documents are labelled 'restricted', a comparatively low level of secrecy in most official classification systems, this is likely a designation by the shipbuilder DCNS rather than either the French or Indian governments, and probably doesn’t reflect the value of the data. Some of the parameters listed here – acoustic and IR signatures in particular – would normally be held by sub-operating states at Top Secret or above, with a very small number of people in the loop. As my RUSI colleague Peter Roberts, a former Royal Navy officer, told the Hindustan Times, 'acoustic intelligence – the fingerprint of a submarine – is the Holy Grail' of anti-submarine warfare (ASW). But he also warned that pre-construction design data would be imperfect. 'Modelling might provide the parameters that you expect, but the hulls and internal equipment are usually different in reality, and actual noise ratios, frequencies and signatures will be different once built'. In line with this, NDTV has reported that, following an overnight review by the Indian Navy, Parrikar was told 'the specifications in the leaked documents didn't match' those of India’s submarine. It is unclear whether this is accurate, or an effort at saving face over an issue that the opposition has already latched onto.

At the very least, this leak will probably torpedo (sorry) any order for three more Scorpenes, as had seemed likely in December. This comes at a time when India’s submarine fleet has dwindled to dangerously low levels, worsened by a series of accidents, while Chinese naval activity into the Indian Ocean has grown substantially. India has built up its maritime surveillance capability on the Andaman and Nicobar Islands, close to the Malacca Straits, explored the possibility of cooperating on a sound surveillance sensors (SOSUS) chain with Japan and the US, and signed an agreement with Germany to bolster the ASW weapons on its older diesel-electric submarines. Any erosion in the stealthiness of the Scorpene class will complicate these efforts, which India sees as crucial to the maritime balance of power in the region.

Photo courtesy of Flickr user Keerthivasan Rajamani