India must secure sea control in the Bay of Bengal bastion to protect SSBNs like INS Arihant and Arighat, relying on layered anti-submarine warfare (ASW) amid Chinese surveillance threats.

Project Varsha's underground base enables covert submarine deployment, but demands robust denial of adversary subsurface intrusion. Chinese research vessels exacerbate risks by mapping acoustics vital for SSBN stealth.​

Chinese ships gather data on thermoclines, salinity layers, and seabed topography, enabling long-range submarine detection in the bastion. India lacks comprehensive indigenous oceanographic mapping, hindering predictive ASW models for sound propagation. Persistent surveys near Galle and Diego Garcia undermine bastion opacity, compelling urgent hydrographic counter-intelligence.​

Chinese Submarine Incursion Threats

People's Liberation Army Navy (PLAN) Type 093B SSNs and Yuan-class diesel-electrics could penetrate via Malacca Strait, trailing SSBNs during patrols. India's P-8I aircraft and Mihir ASW systems (Low Frequency Variable Depth Sonar [LFVDS]) face numerical deficits against China's expanding undersea fleet bolstered by Pakistan. Bastion viability hinges on choking choke-points with mines and allied patrols from Bangladesh-Myanmar ties.​

Current assets like Shishumar-class submarines and Kamorta corvettes suffer from low acoustic sensor density and integration gaps in networked ASW. Variable Bay depths complicate sonar performance, while civilian-control delays mating warheads reduce SSBN readiness. India requires advanced towed arrays, unmanned underwater vehicles, and hypersonic ASW munitions to match PLAN sophistication.​

Chinese Surveillance Disrupts India's SSBN Bastion Tactics

India employs a bastion strategy for its SSBNs in the Bay of Bengal, leveraging Project Varsha's underground facilities near Visakhapatnam to shield submarines from detection while enabling K-4 SLBM launches against Chinese targets.

This approach confines SSBN patrols to defended waters, protected by surface assets like the third aircraft carrier and Andaman & Nicobar forces, mirroring Russian Arctic tactics. Chinese research vessels undermine this by mapping acoustics, thermoclines, and seabed features essential for submarine stealth.​

Naval Tactics Amid Vessel Intrusions

The Indian Navy tracks Chinese ships like Lan Hai 101 and Shi Yan 6 in real-time, enhancing protocols to counter AIS-off operations near the EEZ. Tactics include diplomatic protests, P-8I surveillance flights, and ASW patrols to deny intelligence on SSBN transit corridors. Past incidents prompted missile test delays, forcing adaptive scheduling and layered defences to maintain bastion integrity.​

Project Varsha's tunnels allow undetected Bay of Bengal entry, but Chinese surveys near Diego Garcia and Galle ports reveal hydrological data for long-range detection. Dependence on regional ties with Bangladesh and Myanmar grows critical to block Malacca Strait incursions. Without superior sea control, K-15 limitations persist until K-4 deployment, risking first-strike vulnerability.​

India accelerates maritime domain awareness via unmanned systems and QUAD partnerships to match China's oceanographic edge. Enhanced bastion layers—sonar networks, minefields, and hypersonic ASW—aim to preserve second-strike credibility. Persistent vessel presence signals escalation risks, compelling diversified basing beyond Visakhapatnam.​

IDN (With Agency Inputs)