India launches nine-day Sea Vigil-26 coastal defence drill along its newly re-measured coastline

India began the fifth edition of its national coastal defence exercise, Sea Vigil-26, on 11 November, with the Indian Navy acting as lead agency for a nine-day test of security arrangements along the whole coastline and the country's Exclusive Economic Zone, according to a defence release issued through the Press Information Bureau.

The exercise is split into two phases. A Coastal Defence and Security Readiness Evaluation runs from 11 to 17 November, and a sea phase follows on 18 and 19 November. The New Indian Express noted that the sea phase ends about a week before the 18th anniversary of the November 2008 Mumbai attacks.

All coastal states and union territories are taking part, together with fishing and coastal communities. Ships, boats and personnel from the Indian Navy, the Indian Coast Guard, state Coastal Security Police, Customs and other maritime agencies are involved. The release said the ministries of defence, home affairs, ports and shipping, petroleum and natural gas, and fisheries are supporting the drill alongside central and state agencies. The PTI report carried by the Hindustan Times added that the exercise also covers the protection of critical offshore installations such as oil platforms.

This year's edition carries two firsts, according to The New Indian Express. It is the first Sea Vigil since Operation Sindoor, the Indian military operation launched in May 2025 after the Pahalgam terror attack. It is also the first since India officially re-measured its coastline at 11,098.81 kilometres, nearly 48 percent longer than the 7,516.6 kilometre figure used for decades.

Sea Vigil was conceived in 2018 to check the measures put in place after the Mumbai attacks. In November 2008, ten Lashkar-e-Taiba gunmen sailed from Karachi, seized the Indian fishing trawler Kuber, killed its captain and reached Mumbai without being detected, landing in inflatable dinghies. The attacks killed 166 people. The overhaul that followed made the navy responsible for overall maritime security, including coastal and offshore security, and designated its commanders-in-chief at Mumbai, Kochi, Visakhapatnam and Port Blair as commanders-in-chief for coastal defence.

The exercise has grown with each edition. The first, in 2019, involved nearly 150 ships and 40 aircraft, The New Indian Express reported. The 2024 edition brought together six ministries and 21 organisations, with the National Security Council Secretariat taking part for the first time and the army and air force also drawn in, and its readiness phase audited more than 950 critical coastal sites, including ports, oil rigs, single-point moorings and undersea cable landing points. The PTI report put this year's participation at 21 agencies across six ministries, while the release published by the Press Information Bureau named five supporting ministries.

Sea Vigil also serves as a build-up to the navy's biennial Theatre Level Readiness Operational Exercise, known as TROPEX. The navy said the two drills together are meant to cover the full range of maritime security challenges, from coastal defence and infiltration threats to operations on the high seas, and that running Sea Vigil at national level lets the government assess preparedness at the highest level.

The Free Press Journal reported that security in Mumbai is a particular focus and that the large-scale participation is intended to test coordination between agencies and expose gaps in existing coastal security arrangements, with fishing communities expected to help identify suspicious activity along the shore. None of the reports gave the number of ships or aircraft committed to this year's exercise.