|Preceded by:||Vela class|
|Length:||72.6 m (238 ft 2 in)|
|Beam:||9.9 m (32 ft 6 in)|
|Draught:||6.6 m (21 ft 8 in)|
|Test depth:||300 m (980 ft)|
|Complement:||53 (13 Officers)|
Sindhughosh-class submarines are Kilo-class diesel-electric submarines in active service with the Indian Navy. Their names are in Sanskrit, but in their Roman-alphabet forms sometimes a final short -a is dropped.
The submarines have a displacement of 3,000 tonnes, a maximum diving depth of 300 meters, top speed of 18 knots, and are able to operate solo for 45 days with a crew of 53. The final unit was the first to be equipped with the 3M-54 Klub (SS-N-27) antiship cruise missiles with a range of 220 km.
INS Sindhuvijay has been upgraded with the hydro acoustical USHUS complex and the CCS-MK radio communications system. On 29 August 2014 DAC cleared the long-awaited mid-life upgrade of the four Kilo-class submarines, which would be carried out in Indian shipyards and is likely to cost Rs. 4,800 crore (4,800 million). On 5 November 2014 official sources at HSL said more than 90% of the work has been completed on the seventh submarine of the Sindhughosh class INS Sindhukirti. Scheduled to re-join the fleet on 31 March 2015, she re-entered service on 23 May.
- On 10 January 2008, INS Sindhughosh collided with the cargo ship MV Leeds Castle. The submarine was reported to have sustained superficial damage to its conning tower. As a result, the submarine was out of service for a month. The cargo ship was in restricted shallow waters.
- On 26 February 2010, a fire on board INS Sindhurakshak killed one sailor and injured two others. The fire was due to a defective battery.
- On 14 August 2013 an explosion, followed by a fire, was reported to have occurred on Sindhurakshak. Sindhurakshak sank in the dock.
- On 17 January 2014, Sindhughosh ran aground due to the low tide, while returning to the Naval Dockyard, Mumbai.
- On 26 February 2014, smoke was detected on board INS Sindhuratna resulting in 7 sailors being rendered unconscious and two dead. Those unconscious were airlifted to hospital 
Ships of the class
|Name||Pennant||Builder||Homeport||Commission date||Status||Meaning of name|
|Mumbai||30 April 1986||Refitted to project 08773 2002-2005 at Zvezdochka shipyard||Battle-cry/rumour/report of the Sea|
|Sindhudhvaj||S56||Sevmash||Mumbai||12 June 1987||To be Refitted to project 08773||Flag of the Sea|
|Sindhuraj||S57||Sevmash||Mumbai||20 October 1987||To be Refitted to project 08773||King of the Sea|
|Sindhuvir||S58||Sevmash||Mumbai||26 August 1988||Refitted to project 08773 1997-1999 at Zvezdochka shipyard||Valiant of the Sea|
|Sindhuratna||S59||Sevmash||Mumbai||22 December 1988||Refitted to project 08773 2001-2003 at Zvezdochka shipyard||Jewel of the Sea|
|Sindhukesari||S60||Sevmash||Vishakhapatnam||16 February 1989||To be Refitted to project 08773||Lion of the Sea|
|Sindhukirti||S61||Sevmash||Vishakhapatnam||4 January 1990||Refitted to project 08773 from 2007-2015 in her home base Vishakhapatnam||Fame of the Sea|
|Sindhuvijay||S62||Sevmash||Vishakhapatnam||18 March 1991||Refitted to project 08773 2005-2007 at Zvezdochka shipyard||Victory of the Sea|
|Sindhurakshak||S63||Sevmash||Mumbai||24 December 1997||Refitted to project 08773 09.08.2010-2012 at Zvezdochka shipyard.
Exploded and sank in Mumbai 14 August 2013
|Protector of the Sea|
|Sindhurashtra||S65||Sevmash||Vishakhapatnam||19 July 2000||To be Refitted to project 08773||Sea Country|
- Russian shipyard to float upgraded Indian Navy Kilo class submarine
- "Even Hudhud could not stop INS Sindhukirti refit at HSL". 5 Nov 2014.
- "Russia delayed sub refit to weaken shipyard?". Business Standard. 2 September 2014. Retrieved 8 September 2014.
- "Navy gets INS Sindhukirti back". Business Standard. 23 May 2015. Retrieved 24 May 2015.
- News report on Submarine collision
- Fire Mishap on INS Sindhurakshak
- "Indian submarine hit by explosion at Mumbai port". BBC News. 14 August 2013. Retrieved 14 August 2013.
- "Submarine hits ground due to low tide, no casualty". 19 January 2014. Retrieved 27 February 2014.
- "Two officers died in fire on board submarine INS Sindhuratna, confirms navy". NDTV News. 27 February 2014. Retrieved 27 February 2014.
- Kesari is lion in Sanskrit
- Rashtra means country/land in Sanskrit
INS Sindhurakshak at Portsmouth Harbour, UK in 2013