What is INS Shalki?

About INS Shalki:

• It is a Shishumar-class diesel-electric submarine.
• It is also the first-ever submarine that was built in India. 
• It was constructed under licence by the Mazgaon Dock Limited in Mumbai.
• It was commissioned into the Indian Navy on 7 February 1992.
• Specifications:
  • It has a 6.5 m (21 ft) beam, 6 m (20 ft) draught, and is 64.4 m (211 ft) in length.
  • It carries40 people on board including 8 officers. 
  • The displacement of INS Shalki is 1450 tons on surfaces, 1850 tons submerged.
  • Its range is snorting8,000 nautical miles (15,000 km) at 8 kn (15 km/h).
  • The speed ranges from 11 knots surfaced (i.e., 20 km/h) and 22 knots submerged (41 km/h).

Q1: What is INS Arighat (S3)?

It is an upgraded variant of the Arihant-class submarine. It is the second nuclear-powered ballistic missile submarine being built by India under the Advanced Technology Vessel (ATV) project. It can accommodate more K4 missiles than S2.

Source: Indian Navy submarine INS Shalki arrives in Colombo for formal visit