Coastline of India

Also called: Revised length of India's coastline · Topic: India: Location, Size, Extent and Divisions · NCERT: Class 7, Ch 1 "Geographical Diversity of India"; Class 7, Ch 2 "India and Her Neighbours"; Class 10, Ch 7 "Lifelines of National Economy"; Class 11, Ch 1 "India - Location"

Meaning

The coastline of India is the total length of the line where India's land meets the sea. It includes the mainland and all its islands. The official figure was revised in 2025 to 11,098.81 km, up from the older 7,516.6 km [2][3].

It matters because India's coast supports its ports, fishing and its large sea area (EEZ). The 2025 jump in length is also a clear example of the coastline paradox, and UPSC can test both the new and the old figures.

Explanation

Why India has a long coast

• The Peninsula sets the shape.
• Peninsular India juts south into the Indian Ocean.
• The Arabian Sea lies to its west and the Bay of Bengal to its east.

• So the coast wraps around three sides of the Peninsula.

• Islands add more coast.

• The Andaman and Nicobar Islands in the Bay of Bengal have about 572 islands.
• Lakshadweep in the Arabian Sea has about 36 islands.
• Each island has its own shoreline, so the total grows.

The old figure and the new figure

• Old (NCERT) figure:
• Mainland: 6,100 km.
• With islands: 7,516.6 km (≈7,517 km).

• It came from coarse, small-scale maps of the 1970s.

• Revised figure (2025): 11,098.81 km [2][3].

• Who measured it: the National Hydrographic Office (NHO), working with the Survey of India (SoI) [3]. The work ran in 2023–24.
• How: they used GIS (Geographic Information System: computer software that stores and measures map data). They traced the High-Water Line (HWL), which is the line the sea reaches at high tide, using high-resolution data from the latest surveys [3]. They used finer 1:250,000 digital maps.
• Who approved it: first the Coastal Protection and Development Advisory Committee (CPDAC), after every coastal state and UT agreed. Then the Ministry of Ports, Shipping and Waterways made it official in a circular dated 29 April 2025 [3].

Why the figure jumped by about 48%: the coastline paradox

• Coastline paradox: the more closely you measure a wiggly coast, the longer it gets.
• How it worked for India:
• On the old coarse maps, a bay or creek looked like a straight line.
• The finer maps showed the edges of bays, creeks and estuaries (an estuary is the wide mouth of a river where it meets the sea).
• The new maps also counted more small islands.

• Result: about 3,582 km more coast, an increase of about 48%.

• No new land was added. India's territory stayed the same. Only the way of measuring got better.

Who has the longest coast (revised 2025)

Unit	Revised length	Note
Andaman and Nicobar Islands (UT)	3,083.50 km [2]	Longest of all states and UTs
Gujarat (state)	2,340.62 km [2]	Longest among states; biggest gain (+1,125.9 km) [3]
Tamil Nadu (state)	1,068.69 km [2]	Long east and south coast
Lakshadweep (UT)	144.80 km [2]	Small coral islands
India total	11,098.81 km [2]	NCERT: 7,516.6 km

• Gujarat gained the most because the Gulf of Kachchh and the Gulf of Khambhat cut deep into it. Their many creeks added the most length in the recount [3].
• Andaman and Nicobar beats Gujarat because hundreds of islands each add their own shoreline [2].

Where it occurs

• 9 coastal states, west to east along the coast:
• On the Arabian Sea: Gujarat → Maharashtra → Goa → Karnataka → Kerala.
• On the Bay of Bengal: Tamil Nadu → Andhra Pradesh → Odisha → West Bengal.

• Tamil Nadu's southern tip near Kanniyakumari faces the open Indian Ocean.

• 4 coastal Union Territories:

• Dadra and Nagar Haveli and Daman and Diu (Arabian Sea side).
• Puducherry: mostly on the Coromandel coast (Bay of Bengal). Its Mahe part is on the Malabar coast in Kerala.
• Lakshadweep (Arabian Sea): low coral islands (built by tiny sea animals called coral polyps) at 8°–12°N, 71°–74°E.

• Andaman and Nicobar Islands (Bay of Bengal): mostly hilly islands that are the tops of an undersea mountain chain, at 6°–14°N, 92°–94°E.

• Channels near the island coasts:

• Ten Degree Channel: separates the Andaman group from the Nicobar group.
• Nine Degree Channel: separates Minicoy from the main Lakshadweep group.
• Eight Degree Channel: separates Minicoy from the Maldives.

• Indira Point (Great Nicobar) is India's southernmost point.

• Coastline paradox in the world: Britain's coast is the textbook example. Norway's coast, with its many fjords, behaves the same way.

Don't confuse with

• Coastline length vs land frontier: the coastline is India's border with the sea. The land frontier is India's border with neighbouring countries. They are two separate measurements.
• 11,098.81 km vs 7,516.6 km vs 6,100 km: 11,098.81 km is the revised 2025 total. 7,516.6 km is the old NCERT total with islands. 6,100 km is the old mainland only figure. Read the question to see which one it asks for.
• Longest coast overall vs longest among states: the Andaman and Nicobar Islands (a UT, 3,083.50 km) have the longest coast of all [2]. Gujarat (2,340.62 km) is longest among states only [2].
• Coastline vs EEZ: the coastline is a length in km. The EEZ (Exclusive Economic Zone) is a sea area, reaching up to 200 nautical miles from the coast, where only India may use the fish, oil, gas and minerals under UNCLOS (the UN Convention on the Law of the Sea). India's EEZ is about 2.02 million sq km [4].

Prelims Hooks

• India's coastline (revised, MoPSW circular of 29 April 2025): 11,098.81 km [3]. The old figure was 7,516.6 km, and the mainland alone was 6,100 km (NCERT).
• Remeasured by the National Hydrographic Office with the Survey of India, using GIS and the High-Water Line. Approved by the CPDAC [3].
• Cause of the ~48% rise: the coastline paradox. Finer maps traced more bays, creeks and estuaries. No new territory was added.
• Trap: Andaman and Nicobar (3,083.50 km) > Gujarat (2,340.62 km) > Tamil Nadu (1,068.69 km) [2]. Gujarat had the biggest gain (+1,125.9 km) [3].
• 9 coastal states and 4 coastal UTs. Trap: Ladakh, J&K, Delhi and Chandigarh are landlocked.
• NCERT figures differ: Class 11 gives 7,516.6 km; the older Class 7 book says "over 7,500 km"; the new Class 7 book says "approximately 11,100 km".

Mains Points

• Coastline paradox and its effects (GS-I): the jump from 7,516.6 km to 11,098.81 km shows that a measured length depends on map scale.
• A longer official coast changes how far CRZ rules reach (Coastal Regulation Zone: the strip along the coast where building is controlled).

• It also changes coastal-security planning, coastal-erosion maps and the funds given to coastal states.

• Long coast as a strength (GS-III): about 11,099 km of coast and an EEZ of about 2.02 million sq km [4] support:

• sea trade through ports under the Sagarmala port programme;
• fisheries, mostly in Kerala, Gujarat, Tamil Nadu, Andhra Pradesh and Maharashtra;
• offshore oil and gas at Mumbai High and the Krishna–Godavari basin;
• the Blue Economy (income from ocean resources such as fishing, shipping, seabed minerals and tourism).

• The island coasts sit near the Strait of Malacca and the Nine and Eight Degree Channels. This gives India a strong position on major sea lanes, backed by the tri-service Andaman and Nicobar Command [4]. Mapping the continental shelf under UNCLOS may add about 1 million sq km more sea area [4].

• Long coast as a risk (GS-III, disasters):

• Cyclones form often over the warm, shallow Bay of Bengal. They hit Odisha, Andhra Pradesh, West Bengal and Tamil Nadu with strong winds, heavy rain and a storm surge (sea water pushed inland by the storm).
• Tsunamis: the 2004 Indian Ocean tsunami hit Tamil Nadu and the Andaman and Nicobar Islands.
• Sea-level rise threatens low coasts and islands such as the Sundarbans and Lakshadweep.
• Responses: tsunami and storm-surge warnings from INCOIS, mangrove shelterbelts (belts of mangrove trees that soften waves) and coastal zone management plans.

Read more

• Coastline and the island territories