BharatNotes India's coastline was officially revised in 2023–24 by the Survey of India and the National Hydrographic Office using advanced geospatial mapping at a finer scale (1:250,000 vs the old 1:4,500,000 used in the 1970s). The revised total coastline is 11,098.81 km (mainland: 7,870.51 km; island coastline: 3,228.30 km) — a 47.7% increase from the old figure of 7,516.6 km. The coastline will be reviewed every 10 years. There are 9 coastal states and 4 coastal UTs (Daman & Diu, Lakshadweep, Puducherry, Andaman & Nicobar Islands). Gujarat retains the longest state coastline (2,340.62 km, revised from the earlier ~1,600 km figure), followed by Tamil Nadu (1,068 km) and Andhra Pradesh (1,053 km). UPSC tests the names of coastal plains, associated ports, lagoons, and the difference between the west coast (rocky, indented, natural harbours) and the east coast (deltaic, straight, cyclone-prone).
UPSC Alert (2024): The old figure of 7,516.6 km is now superseded. The revised figure of 11,098.81 km was reported in 2024 under the National Maritime Security Coordinator and is increasingly appearing in current affairs questions. Be ready with both figures and the reason for the change (improved geospatial methodology, not territorial change).
West Coast — Gujarat to Kerala
The west coast is narrower (average 64 km wide), rocky, with submerged coastline, natural harbours, and backwaters (kayals). It does not form large deltas as rivers are shorter.
| Region / Coastal Plain Name | States | Features | Key Ports | Major Cities / Lagoons |
|---|---|---|---|---|
| Kachchh / Rann Coast | Gujarat | Gulf of Kachchh; Great Rann and Little Rann; salt flats; flamingo nesting | Kandla (Deendayal Port — major port); Mundra (Adani, largest private port in India) | Bhuj; Rann of Kachchh; Marine NP (Gulf of Kachchh) |
| Saurashtra / Kathiawar Coast | Gujarat | Rocky peninsula; Gulf of Khambhat; Gir coast (Asiatic Lion territory) | Pipavav; Bedi; Okha; Veraval (fishing) | Jamnagar; Junagadh; Somnath Temple; Velavadar (Blackbuck NP) |
| Gulf of Khambhat (Cambay) | Gujarat | Funnel-shaped; extreme tidal range (11 m); Narmada and Mahi estuaries; tidal power potential | — | Bharuch (Broach); Cambay town |
| Konkan Coast | Maharashtra, Goa, part of Karnataka | 500-700 km long; rocky, indented; laterite cliffs; 50-80 km wide; submerged coastline type | Mumbai (JNPT — Jawaharlal Nehru Port, busiest in India); Mormugao (Goa); New Mangalore (Karnataka) | Mumbai; Panaji (Goa); Mangaluru; Karwar; Sindhudurg Fort |
| Kannad (Karnataka) Coast | Karnataka | Between Goa and Kerala; narrow; Western Ghats close to sea | New Mangalore Port | Mangaluru; Udupi; Karwar; Murudeshwar |
| Malabar Coast | Kerala | Famous for backwaters (Kayals); lagoons, spice trade historically; wet throughout | Kochi (Cochin) — natural harbour, oldest port; Vizhinjam International Seaport — India's first deep-water transhipment port, inaugurated May 2025 by PM Modi; Phase I capacity 1 million TEUs (operational Dec 2024); all phases to be completed by 2028 | Thiruvananthapuram; Kochi; Kozhikode (Calicut — Vasco da Gama landed 1498) |
East Coast — West Bengal to Tamil Nadu
The east coast is wider (average 100-130 km), formed by large river deltas, relatively straight, with lagoons and sandbars. Cyclone-prone.
| Region / Coastal Plain Name | States | Features | Key Ports | Major Cities / Lagoons |
|---|---|---|---|---|
| Northern Circars / Utkal Plains | West Bengal, Odisha, northern AP | Between Mahanadi and Krishna rivers; large deltaic plains; Mahanadi, Rushikulya, Subarnarekha estuaries; Chilika Lake | Paradip (Odisha) — major port; Kolkata/Haldia (WB) | Bhubaneswar; Puri; Cuttack; Vishakhapatnam |
| Chilika Lake | Odisha | Largest coastal lagoon in India; Asia's largest brackish water lake; Nalabana Island; Irrawaddy Dolphin; Ramsar site 1981 | — | Chilika; Puri district |
| Andhra / Coromandel Northern | Andhra Pradesh | Krishna-Godavari delta; fertile deltaic plain; aquaculture (shrimp); Kolleru Lake (Ramsar) | Visakhapatnam (Vizag) — major deep-water port; Gangavaram; Kakinada | Visakhapatnam; Vijayawada; Rajamahendravaram (Rajahmundry) |
| Coromandel Coast (proper) | Southern AP, Tamil Nadu | Between Krishna River and Cauvery delta; straight, sandy coast; cyclone-prone; Pulicat Lake (2nd largest lagoon) | Chennai (Ennore/Kamarajar Port); Tuticorin (V.O. Chidambaranar Port) | Chennai; Puducherry |
| Pulicat Lake | TN/AP border | 2nd largest brackish water lake in India; greater flamingo; migratory birds; Sriharikota (ISRO Launch Centre) is on the barrier island between Pulicat and sea | — | Nellore side (AP); Ponneri (TN) |
| Cauvery Delta | Tamil Nadu | Kaveri delta; most fertile zone; "granary of South India"; Colleroon/Kollidam distributary | — | Thanjavur; Kumbakonam; Karaikal |
| Palk Strait and Gulf of Mannar | Tamil Nadu | Shallow; Adam's Bridge (Ram Setu) — chain of shoals to Sri Lanka; pearl oyster fishery historically; Gulf of Mannar Marine Biosphere Reserve | Mandapam; Tuticorin | Rameswaram; Tuticorin (Thoothukudi) |
