Here are the 10 developments in this big story:
The Scorpene project is critical for the Navy's growth. At the moment, the Navy operates only 13 conventionally powered submarines and two nuclear submarines.
Kalvari, India's first Scorpene-class submarine, is completing sea trials and will be commissioned shortly, the Indian Navy has said. It was acquired by the Navy in September last year. The other four submarines are expected to be launched at nine-month intervals after the Khanderi.
Union Minister of State for Defence Subhash Bhamre and Chief of the Naval Staff Admiral Sunil Lanba were present this morning as the Khanderi was separated from the pontoon on which it was assembled.
The Khanderi has superior stealth features and can launch a crippling attack on the enemy with torpedoes and tube-launched anti-ship missiles while it is under water or on surface. The stealth features give the vessel an invulnerability that is unmatched by many submarines, the Indian Navy has said.
The submarine can operate in all theatres, including the tropics and can be used for anti-surface warfare, anti-submarine warfare, intelligence gathering, mine laying and area surveillance.
The assembling of the submarine was a complex task that involved putting together different sections and laying kilometres of cabling and piping in extremely congested compartments.
Till December this year, the submarine will undergo rigorous trials and tests both at harbour and at sea and it will then be commissioned in the Indian Navy as INS Khanderi. The Khanderi is named after an Island fort of the Maratha forces which played a vital role in ensuring their supremacy at sea in the late 17th century, the Navy said.
India is among a few countries in the world which produce conventional submarines. Its submarine arm completes 50 years in December this year. Submarine Day is celebrated on December 8, the day when the first submarine, the INS Kalvari, was inducted into the Indian Navy in 1967.
India joined an exclusive group of countries that build submarines in February 1992, when the first Indian-built submarine INS Shalki was commissioned. Two years later, the INS Shankul was commissioned. Both are still in service.
The primary weapon of the Scorpene submarines being built for the Indian Navy, the Black Shark torpedo, is missing because it is manufactured by a firm linked to the Italian firm Finmeccanica, which has been blacklisted after the Agusta Westland VVIP chopper scam. The Navy is looking to procure alternate torpedoes.