Kalvari-class submarine (1967)

Kalvari-class submarines were the first submarines inducted into the Indian Navy. They were variants of the early Soviet s. Four of the class served in the Indian Navy. Four additional variants of the later Foxtrot class were inducted as the.

INS Kursura (S20) has been preserved as a museum on Ramakrishna Mission Beach in Vishakhapatnam. The sail of the lead vessel, INS Kalvari (S23) is also on display at the Vishakhapatnam city museum.