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Anti-submarine shallow water craft: Navy commissions third Cochin-built ship, INS Mangrol

By CAShorts DeskPublished Source: All India Radio News (newsonair.gov.in); The Hindu, 12 October 2026

Anti-submarine shallow water craft: Navy commissions third Cochin-built ship, INS Mangrol
Illustration (AI-generated)

Cochin Shipyard Limited is building eight Anti-Submarine Warfare Shallow Water Craft to hunt submarines in India's coastal waters. The third, INS Mangrol, was commissioned at Naval Dockyard Mumbai on 12 October 2026. It carries the Abhay hull-mounted sonar, lightweight torpedoes, an anti-submarine rocket launcher and the Mareech torpedo decoy. The Navy puts its indigenous content above 80%.

Syllabus: Prelims · Current Affairs & IR; GS3 · Indian Achievements in S&T; GS3 · Security Forces & Agencies

Why it matters

A cargo crew sailing into Mumbai and a fishing family working off the Gujarat coast both depend on safe coastal waters. Larger warships face limits close to shore, so the Navy needs small, nimble craft that can stay inshore, listen with sonar and strike with torpedoes and rockets, while patrol aircraft and helicopters search further out. Each new craft adds to that screen around ports and harbours. The ship also shows how much of a warship India now makes itself: the Navy puts Mangrol's indigenous content above 80%, so more of the money, the repair work and the skill to upgrade the ship stays with Indian yards and suppliers.

Prelims pointers

  • Anti-Submarine Warfare Shallow Water Craft: sixteen ordered for the Indian Navy, eight each from Cochin Shipyard Limited, Kochi, and Garden Reach Shipbuilders and Engineers, Kolkata.
  • Cochin Shipyard Limited: public sector undertaking under the Ministry of Ports, Shipping and Waterways; it built INS Vikrant, India's first indigenous aircraft carrier.
  • Sonar (Sound Navigation and Ranging): active sonar sends out a sound pulse and times its echo; passive sonar only listens for the noise a target makes.
  • Seawater soon absorbs radio waves, so radar cannot find a submerged submarine; sound travels about 1,500 metres a second in seawater, over four times its speed in air.
  • Hull-mounted sonar sits in a dome under the ship's hull; a towed array sonar trails far behind on a cable, away from the ship's own noise.
  • Waterjet propulsion: a pump inside the hull draws in water and forces it astern as a jet; the nozzle steers, so no propeller or rudder hangs below the hull.
  • Abhay sonar and the Mareech decoy were both developed by the Defence Research and Development Organisation (DRDO).
  • Make in India: launched in 2014, nodal Department for Promotion of Industry and Internal Trade (DPIIT). Aatmanirbhar Bharat Abhiyan: announced in 2020.

Practise a UPSC-style question

Consider the following statements about INS Mangrol, recently commissioned into the Indian Navy:

1. It was built by Garden Reach Shipbuilders and Engineers, Kolkata.

2. It is powered by three diesel engines with waterjet propulsion.

3. Besides anti-submarine warfare, it can undertake underwater surveillance and mine warfare-related tasks.

Which of the statements given above is/are correct?

  1. (a) 1 and 2 only
  2. (b) 2 and 3 only
  3. (c) 1 and 3 only
  4. (d) 1, 2 and 3
Show the answer

Answer: (b) 2 and 3 only

1 is incorrect: INS Mangrol was built by Cochin Shipyard Limited, Kochi, the third of the eight such craft it is building. 2 is correct: three diesel engines drive waterjets, giving the ship high manoeuvrability in shallow water. 3 is correct: besides hunting submarines, it can carry out underwater surveillance, low-intensity maritime operations and mine warfare-related tasks.

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