INS Nireekshak is a diving support vessel (DSV) of Indian Navy. It can also function as interim submarine rescue vessel (SRV). INS Nireekshak was originally built by M/s Mazagon Dock Limited, Mumbai for ONGC's offshore oil exploration work having a dynamic position facility and a recompression chamber. It was however acquired on lease with an option for purchase by Indian Navy and was commissioned on 8 June 1989. The ship was modified and refitted with the diving bell and other rescue equipment removed from the Russian Submarine rescue vessel INS Nistar in a dry dock. In March 1995 the purchase option was invoked and the vessel was formally re-commissioned on 15 September 1995. The ship is equipped with two Deep Submergence Rescue Vehicles (DSRV), capable of taking 12 men to 300 meters tog