India has employed a strategic deception tactic using repeated issuance and cancellation of NOTAMs (Notices to Airmen) during late 2025 to counter Chinese surveillance vessels monitoring potential ballistic missile tests in the Bay of Bengal.

This "cat-and-mouse" approach allowed India to study Chinese response patterns without revealing actual test data, amid heightened tensions over Beijing's dual-use research ships equipped for telemetry collection.

NOTAM Timeline

India issued multiple large no-fly zones over the Bay of Bengal, primarily from Odisha's Chandipur range, only to cancel them abruptly as Chinese vessels positioned themselves.

Nov 25-30, 2025: NOTAM for Dec 1-4, ~3,500 km zone (Chandipur to Visakhapatnam coast), suggesting K-4 SLBM test (3,500 km range).

Early Dec 2025: NOTAM for Dec 11, ~1,190 km shorter zone, cancelled shortly after.

Dec 9, 2025: NOTAM for Dec 17-20, expanded from 2,250 km to 3,550 km, cancelled Dec 16.

Mid-Dec 2025: NOTAM for Dec 22-24, ~3,240 km zone, status unclear but aligned with pattern; actual K-4 validation reportedly occurred covertly later.

These rollbacks were rare and timed just before deadlines, forcing Chinese ships to expend resources on futile deployments.

Chinese Surveillance Response

China deployed up to five dual-use "research" vessels—Lan Hai 101, Shi Yan 6, Shen Hai Yi Hao, Lan Hai 201, and Da Yang Yi Hao—capable of tracking missile trajectories, sonar mapping for submarine modelling, and telemetry interception.

Vessels arrived 3-7 days post-NOTAM, exposing transit speeds (e.g., 15-20 knots) and coordination from bases like Sanya.

Strategic Deception Tactics

India's playbook disrupted surveillance through low-cost manoeuvres.

Range Manipulation: Issued oversized zones (3,500+ km) to lure ships into broad positioning, then cancelled, wasting fuel and revealing patrol envelopes.

Abrupt Cancellations: Timed post-arrival (e.g., Dec 16 after Dec 14 entry), denying data collection windows.

Actual Test Secrecy: K-4 SLBM from INS Arighaat conducted Dec 23 covertly, post-diversions, validating nuclear deterrent without telemetry leaks.

Multi-Theatre Feints: Dec 5 Arabian Sea NOTAM near Pakistan (200 nm from Karachi) split Chinese/Pakistani attention.

This yielded intel on Chinese response times (72-96 hours), ship endurance (~30 days), and gaps in India's counter-tracking.

China's intrusions support submarine tech modelling and IOR expansion via ports like Hambantota, challenging India's deterrence amid Agni/K-series advancements. India's tactic echoes 2022 Yuan Wang 06 denial and 2024 Agni-5 MIRV test, where similar feints blinded surveillance. Experts like Abhijit Singh note Beijing's focus on submarine-launch data; cancellations clear commercial traffic for clean Indian tests. By Jan 2026, this has enhanced India's operational security, forcing China to recalibrate deployments.

​IDN (With Agency Inputs)