INS Nipat (K86) was a Vidyut-class missile boat of the Indian Navy.

During the Indo-Pakistani War of 1971, INS Nipat was part of the Operation Trident strike force.

Late that evening, around 70 miles south of Karachi, the Nipat detected two targets about 42 miles to the northeast, later identified as the merchant vessel, MV Venus Challenger, chartered by the Pakistan Navy to carry US ammunition to East Pakistan and its escort PNS Shah Jahan, a C-class destroyer.

Venus Challenger, carrying ammunition for the Pakistani forces, exploded immediately after the missile hit and eventually sank 23 nmi (43 km; 26 mi) south of Karachi.

Two missiles were launched; one misfired, but the other hit the oil tanks, which burned and were destroyed completely.