The SSK Scorpene attack submarine is a diesel-electric submarine capable of firing both conventional and nuclear missiles. It is built by the French state-owned DCN International.

As part of the deal with India, the submarines would be armed with EADS SM-39 Exocet anti-ship missiles.

Displacing 1,700 tonnes, it is 219 feet long and has a speed of over 20 knots. It can remain at sea for about 50 days with a crew of 31, and can dive to a depth of more than a thousand feet.

According to Indefence.com, among its performance characteristics what is 'outstanding is the maximum operating depth (without limit to he number of cycles) greater than 300 metres, maximum submerge speed of more than 20 knots, submerged range at 100 percent battery usage and speed of four knots for 134 hours/536 miles.

The Scorpene was carefully conceived bearing habitation in mind. Its complement of 31 with the possibility of quartering six more in stowed berths. It has one cabin for the captain, one for 5/6 officers, two for 5/6 petty officers, and one for 15 ordinary seamen. It has individual berths and lockers for everyone, two toilets, two showers, four washbasins, and three messes.

The quarters are acoustically insulated from the platform on elastic insulators and there is air-conditioning in all quarters and operations areas. The Scorpene can operate with DSRV rescue vehicles, which the Indian Navy is hunting for.

The DCN website says the Scorpene blue-water submarines offer true multi-role capabilities. Its new-generation combat system and state-of-the-art underwater weapons represent significant threats for enemy submarines, surface combatants and shipping.

Excellent availability (240 days/year) and endurance (50-day patrols) ensure optimal utilization. Thanks to high-level automation, the boat requires a complement of just 31 (three nine-person watches plus four others). For maximum efficiency, all watch personnel work in the main control room throughout a normal eight-hour watch.

An array of advanced technologies contribute to excellent acoustic discretion and survivability. Scorpene submarines also offer advanced capabilities for mine warfare, intelligence gathering and special operations.

The Scorpene family is being developed in cooperation with Izar of Spain. Two Scorpene submarines are under construction for the Chilean Navy and Malaysia has ordered two for entry into active service in 2007 and 2008.

How much will it cost?

The cost is yet to be officially disclosed. But according to globalsecurity.org, the six Scorpene submarines will cost approximately $4.6 billion. In 2002, it was estimated at $ 3.2 billion, but the prolonged negotiations kept pushing the price up. However, other estimates put the cost at $2 billion, with the French apparently agreeing to bear some of the brunt of inflation.

Where will they be built?

The submarines will be built with French knowhow and assistance at the Mazagon dockyard in Mumbai.  The first submarine is expected to be commissioned in 2010.

The project is expected to be handled by France's [Images] Armaris, the marketing arm of state-owned DCN International, and Thales SA, one of the world's largest defence electronics firms.