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 .
has been preserved as a museum on Ramakrishna Mission Beach in Visakhapatnam.[1] The sail of the lead vessel, is also on display at the Visakhapatnam city museum.
| Name | Pennant | Builder | Commissioned | Decommissioned | Status |
|---|---|---|---|---|---|
| S23 | Sudomekh | 8 December 1967 | 31 May 1996 | Sail on display | |
| S22 | Sudomekh | 6 December 1968 | 18 October 1989 | Sail on display | |
| S21 | Sudomekh | 4 September 1969 | 1 August 2003 | ||
| S20 | Sudomekh | 18 December 1969 | 27 September 2001 | As a museum | |