Designed by the Indian navy, the INS Vikrant is the largest warship to be built in the country. PHOTO: COUTESY/COCHIN SHIPYARD LTDIndia will formally commission its first home-built aircraft carrier on Friday, the culmination of 17 years of construction and tests as the country seeks to catch up with regional rival China and its far larger naval fleet. “Otherwise the aircraft carrier will not be able to be exploited optimally,” the retired naval captain added. With the Vikrant’s entry, India can deploy an aircraft carrier on both its eastern and western seaboards and expand its maritime presence, although the Indian navy still lags behind key regional rival, China. India’s existing fleet includes one aircraft carrier, 10 destroyers, 12 frigates and 20 corvettes.