INS Nistar was a submarine rescue vessel of the Indian Navy. It was bought from reserve stock of the USSR in 1969 and was commissioned by the Indian Navy in 1971. The ship having a displacement of 800 tonnes had the capability of rescuing the crew of a disabled submarine from deep depths, using a "rescue bell", by the dry escape method, which avoided problems associated with decompression. Nistar was used in December during Indo-Pakistani War of 1971 to locate Pakistan Navy submarine PNS Ghazi, which sank off the port of Vizag.