The first of a series of indigenously-built Scorpene-class submarines was commissioned into the Indian Navy on Thursday with Prime Minister Narendra Modi saying in Mumbai that it heralded "a significant new era" in India's defence and security.
The submarine INS Kalvari was built by the Goa-based Mazagon Dock Limited (MDL) with technological collaboration from French industrial group DCNS, which specialises in naval defence.
Kalvari, which means tiger shark in the local language, is the first of six submarines that are to join the Navy under a $3.5bn agreement signed between the state-owned MDL and DCNS.
The submarine measures 67.5 metres in length and 12.3 metres in height, according to the Indian Navy. It can carry 18 torpedoes, travel up to 1,020 kilometres under water and has a silent diesel-electric motor. 
INS Kalvari is the first submarine to be commissioned into the Navy in 17 years amid concerns over security threats in the Indian Ocean including from terrorists, piracy and drug trafficking.
India previously had an ageing fleet of 16 submarines compared to China's 68, Russia's 63 and the United States' 70.