Kalvari, the first of the six Scorpene-class submarines handed over by shipbuilder Mazagon Dock Limited, will be commissioned into the Navy by Prime Minister Narendra Modi here tomorrow. The prime minister will unveil its plaque at the commissioning ceremony tomorrow, an official told PTI. This will be preceded by reading out the commissioning warrant, hoisting of colours and breaking of commissioning pennant with national anthem, the official said. Pennant is a tapering flag on a ship, especially one flown at the masthead of a vessel in commission. Defence Minister Nirmala Sitharaman, Navy chief Admiral Sunil Lanba, Vice Admiral Girish Luthra, Flag Officer Commanding of the Western Naval Command, and top defence officials will attend the commissioning ceremony. "Kalvari underwent around 120 days of extensive sea trials and tests for various equipment," the official said, adding the vessel is expected to bolster India's maritime prowess. The submarines, designed by French naval defence and energy company DCNS, are being built by Mazagon Dock Limited (MDL) in Mumbai as part of Project-75 of the Indian Navy. "The technology utilised in the Scorpene has ensured superior stealth features such as advanced acoustic silencing techniques, low radiated noise levels, hydro-dynamically optimised shape and the ability to launch a crippling attack on the enemy using precision guided weapons," an official of the MDL said. Kalvari is named after the dreaded tiger shark, a deadly deep sea predator of the Indian Ocean. The first Kalvari, commissioned on December 8, 1967, was also the first submarine of the Indian Navy. It was decommissioned on May 31, 1996 after nearly three decades of service.