Chennai, Feb 15 (ANI): The world’s oldest active aircraft carrier, INS Viraat, is on its final journey.It was docked at Chennai port on Monday before it is due to be decommissioned later this year. The ship entered service on May 12, 1987 and is also affiliated to the Garhwal Rifles (infantry regiment) of the Indian Army. The navy’s aircraft carrier guarded India's maritime borders for nearly 60 years. Captain said that the cost of maintaining and running it is becoming more than the cost benefited. With the time all the machineries get old. Kochi INS Vikrant is likely to replace INS Viraat. The mighty aircraft carrier has seen 18 Commanding Officers of which three went on to become Chiefs of Naval Staff. The ship has done over 40,000 hours of steaming and traversed over 5,00,000 nautical miles across the proverbial seven seas. The ship has undertaken over 20,000 hours of flying from its deck.