Littoral waters are emerging as the weakest link in India's maritime security architecture. Examine the role of indigenous shallow-water ASW platforms in addressing this gap.

Littoral waters are the shallow, noisy coastal zone. Submarines are hardest to detect here, and deep-draught frigates operate poorly. The seaborne 26/11 attack showed how exposed this zone is. India's indigenous Anti-Submarine Warfare Shallow Water Craft (ASW-SWC) programme is a focused but partial answer. Its latest ship, INS Mangrol, was commissioned on 12 Oct 2026 [1].

Why littorals are the weak link

• Shallow depth, seabed clutter and dense fishing and merchant traffic make sonar detection harder and infiltration easier.
• The ageing Abhay-class corvettes have left a coastal ASW gap that must be filled [5].

Role of indigenous ASW-SWCs

• Inshore reach: a draught of only 2.7 m, with hull-mounted and low-frequency variable-depth sonar [4].
• Multi-role: ASW, underwater surveillance, LIMO and mine warfare [2]. Their mine-laying capability can deny an enemy the approaches to our ports [3].
• Agility: diesel-driven waterjets suit confined waters [2].
• Scale and spread: 16 ships, 8 each from GRSE and CSL [5][3]. Both seaboards are covered, with Arnala at Visakhapatnam [4] and Mahe at Mumbai [3].
• Self-reliance: over 80% indigenous content, with MSME participation [2]. A private yard, L&T Kattupalli, also builds hulls [6].

Limitations

• Delays: the first ship was due within 42 months of the 2019 contract [5], but Arnala was commissioned only in June 2025 [4]. This repeats the lead-ship delays CAG traced to late drawings, steel shortages and weak DPSU yards [7].
• Depth of indigenisation: the "80%" figure does not show whether the sonar, weapons or engines are imported. CAG found that earlier ASW corvettes fell short of the anti-submarine capability set in their contract [8].
• Two designs for one requirement mean two sets of spares, training and maintenance.
• Mine-laying is not mine-clearing: the old Mangrol (M85) was a minesweeper [1]. The gap in mine countermeasure vessels remains.

Way forward

• Develop more than one supplier for critical sensors, and measure indigenisation system by system.
• Fast-track dedicated mine countermeasure vessels.
• Network ASW-SWCs with patrol aircraft, coastal radars and the Coast Guard for layered maritime domain awareness.

ASW-SWCs are turning India's littorals from a blind spot into a guarded frontier. If they are delivered on time, indigenised in depth and networked, they can make the weakest link a first line of defence, in keeping with SAGAR and Aatmanirbhar Bharat.