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 during Indo-Pakistani War of 1971 to locate Pakistan Navy submarine , which sank off the port of Vizag.
"Nistar" was decommissioned on 3 November 1989. Some of her equipment such as diving bell were later bequeathed to diving tender INS "Nireekshak".
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