Important Straits of India (Palk Strait, Ten Degree Channel, Nine Degree Channel)
Geography › Physical Geography of India · Topic 8.15
India has several important straits and channels. The Palk Strait separates Tamil Nadu from Sri Lanka and joins the Palk Bay with the Bay of Bengal, with Adam's Bridge, a chain of shoals, across it. The Ten Degree Channel, about 150 km wide, separates the Andaman Islands from the Nicobar Islands. The Nine Degree Channel separates Minicoy from the rest of Lakshadweep, and the Eight Degree Channel separates Minicoy from the Maldives. The Great Channel lies between Great Nicobar and Sumatra. Several of them lie on busy shipping routes and have strategic value.
5 min read · UPSC Prelims · Geography · Physical Geography of India
At a Glance
- Palk Strait India and Sri Lanka
- Ten Degree Channel Andaman from Nicobar
- Nine Degree Channel Minicoy from Lakshadweep islands
- Eight Degree Channel Minicoy from the Maldives
- Great Channel Great Nicobar from Sumatra
- Exam link UPSC Prelims, Geography: Physical Geography of India
Where Does It Fit?
This topic follows the topic on mountain passes and covers the sea gaps that link or divide waters around India. It prepares for the topic on the coasts and islands of India, where these channels are located. Previous topic: Major Mountain Passes of India (Nathu La, Shipki La, Rohtang, Zoji La, Palakkad Gap). Next topic: Sutlej; Himachal Pradesh and Punjab Hirakud Mahanadi; Odisha Tehri Bhagirathi; Uttarakhand; 260.5 m Sardar Sarovar Narmada; Gujarat…">Multipurpose River Valley Projects and Major Dams of India (Bhakra Nangal, Hirakud, Tehri, Sardar Sarovar).
What Is the Palk Strait?
In short: the Palk Strait is the shallow sea passage between south-east India and northern Sri Lanka.
- Location: between Tamil Nadu (Rameswaram and the Pamban area) and the Mannar and Jaffna regions of Sri Lanka. It links the Bay of Bengal in the north-east with the Palk Bay, and the Gulf of Mannar in the south.
- Adam’s Bridge (Ram Setu): a chain of limestone shoals and sandbanks, between Pamban Island and Mannar Island, which makes the strait shallow and unfit for large ships.
- Sethusamudram Shipping Canal Project: a proposal to dredge a channel through the shoals to shorten the route around Sri Lanka; it has been debated for its cost, environmental impact and the cultural importance of the Ram Setu, and has not been completed.
- Fishing and boundary: the strait is a rich fishing ground. Maritime boundary agreements were made between India and Sri Lanka in 1974 and 1976, and fishermen’s disputes, with arrests on both sides and the issue of the Katchatheevu islet, are a recurring concern in relations.
- Bridge: the Pamban rail bridge links Rameswaram island with the mainland, and a new vertical-lift rail bridge was opened there in 2025.
Which Channels Cross the Island Territories?
| Channel | Separates | Importance |
|---|---|---|
| Ten Degree Channel | Little Andaman (Andaman group) from Car Nicobar (Nicobar group); about 150 km wide at 10° N | A busy route for ships between the Bay of Bengal and the Andaman Sea towards the Malacca Strait |
| Duncan Passage | South Andaman from Little Andaman | Navigation route inside the Andaman group |
| Preparis and Coco channels | North of the Andaman Islands, near the Coco Islands of Myanmar | Linked to the approach from the Bay of Bengal to the Andaman Sea |
| Great Channel (Six Degree Channel) | Great Nicobar from Sumatra in Indonesia; Indira Point, the southernmost point of India, is near it | Southern entrance to the Malacca Strait; one of the world’s busiest sea lanes |
| Nine Degree Channel | Minicoy from Kalpeni and the other Laccadive islands | Important shipping route between the Arabian Sea and the east |
| Eight Degree Channel | Minicoy from the Maldives | Another route for east-west shipping across the Indian Ocean |
The Ten Degree, Nine Degree and Eight Degree channels lie on routes used by a large part of world sea trade between the Gulf, Africa and Europe on one side and East Asia on the other. Counts of islands differ between sources, as noted in Coastal Plains, Coral Reefs and Islands of India (Andaman and Nicobar Islands, Lakshadweep).
Why Are They Strategically Important?
- Trade routes: a considerable share of the world’s oil and goods moves through the Indian Ocean lanes, and the channels near India lie on those lanes.
- Naval presence: the Andaman and Nicobar Command, India’s first tri-service command, set up in 2001 at Port Blair, watches the western approach to the Malacca Strait. The Indian Navy has a base at Minicoy in Lakshadweep, commissioned in 2024.
- Maritime boundaries: the channels affect the territorial waters and exclusive economic zone of India under the law of the sea, as in United Nations Convention on the Law of the Sea (UNCLOS).
- Environment: heavy traffic brings risks of oil spill and ship strikes on marine life, while the reefs and mangroves near the channels need protection.
- Disaster and communication: these straits and channels also matter for relief after cyclones and tsunamis.
The straits of the world are described in Persian Gulf to Gulf of Oman Gibraltar Atlantic to Mediterranean Bering Asia and…">Important Straits of the World (Strait of Malacca, Strait of Hormuz, Strait of Gibraltar, Bering Strait, Bosphorus). As an analytical point, India’s island territories extend its reach to the busiest waters of the Indian Ocean, which is why the channels are important for security and trade, and not only for geography.
Why Is This Topic Important?
- Map Locations are asked
- Strategy Shipping lanes and security
- Relations India-Sri Lanka fishing
What Came Next?
The next topic covers multipurpose river valley projects and the major dams of India. Next topic: Multipurpose River Valley Projects and Major Dams of India (Bhakra Nangal, Hirakud, Tehri, Sardar Sarovar).
Key People and Terms
- Strait Narrow sea passage between two land masses
- Channel Wider passage between islands
- Adam’s Bridge Shoal chain in the Palk Strait
- Indira Point Southernmost point of India
- Sea lane Regular shipping route
- Katchatheevu Islet in the Palk Strait
Exam Corner
Points to Remember
- Ten Degree Channel separates Andaman from Nicobar.
- Nine Degree Channel lies between Kalpeni and Minicoy.
- Eight Degree Channel separates Minicoy from the Maldives.
- Palk Strait lies between India and Sri Lanka.
- Indira Point is on Great Nicobar.
Do Not Confuse With
- Palk Strait and Palk Bay The passage versus the bay to its north-west
- Ten, Nine and Eight Degree channels Andaman-Nicobar, Minicoy-Laccadives, Minicoy-Maldives
- Strait and channel Between land masses versus between islands
Memory Hook
Ten divides the Andaman, Nine lies by Minicoy, Eight to the Maldives; Palk is Sri Lanka’s tie.
Mains Angle
Questions ask about the strategic role of the island groups. These points add depth.
- Location Straits and channels
- Trade Sea lanes
- Security Island commands
A Question You May Face
An original practice question, not a past paper question.
“Describe the important straits and channels of India and discuss their strategic importance.”
How to Answer
- List Palk Strait and channels.
- Locate Island groups.
- Trade Sea lanes.
- Security Naval bases and boundaries.
GS Relevance
Frequently Asked Questions
Where is the Palk Strait located?
The Palk Strait lies between the Tamil Nadu coast of India and the northern coast of Sri Lanka. It joins the Bay of Bengal to the north-east with the Palk Bay and the Gulf of Mannar, and the shoals of Adam's Bridge across it make the water shallow, so it is unsuitable for large ships.
What is the Ten Degree Channel?
The Ten Degree Channel is a sea passage about 150 km wide at 10 degrees north that separates the Andaman Islands in the north from the Nicobar Islands in the south. It connects the Bay of Bengal with the Andaman Sea and is on a busy shipping route to the Strait of Malacca.
What is the Nine Degree Channel?
The Nine Degree Channel is a sea passage in Lakshadweep that lies at about 9 degrees north, between Kalpeni and Minicoy island. It separates Minicoy from the other Laccadive islands and lies on an important shipping route between the Arabian Sea and the east.
What separates Minicoy from the Maldives?
The Eight Degree Channel separates Minicoy Island, the southernmost island of Lakshadweep, from the Maldives. It lies at about 8 degrees north and, like the Nine Degree Channel, carries a heavy flow of shipping between the Gulf and Europe on one side and East Asia on the other.
What is Adam's Bridge?
Adam's Bridge, also known as Ram Setu, is a chain of limestone shoals and sandbanks lying across the Palk Strait between Pamban Island near Rameswaram in India and Mannar Island in Sri Lanka. It makes the strait shallow, and the proposed Sethusamudram canal project would cut a channel through it.
PYQ Practice — Statement Analysis
1 The Ten Degree Channel separates the Andaman and Nicobar groups.
It is about 150 km wide.
2 The Palk Strait separates India from Myanmar.
It separates India from Sri Lanka.
3 The Eight Degree Channel lies between Minicoy and the Maldives.
Minicoy belongs to Lakshadweep.
4 Adam's Bridge lies in the Palk Strait.
It is a chain of shoals.
Past Mains Questions on This Topic
This topic comes under Physical Geography of India. UPSC Mains questions asked on the matching syllabus topic, year-wise with marks:
Related Topics
Browse the full Geography index