Straits of the World & India

Introduction

A strait is a naturally formed, narrow waterway that connects two larger bodies of water and separates two landmasses. That’s the definition. What makes it worth your time is that straits turn up in UPSC, SSC and State PSC papers year after year, and in 2026 they’re also on the front page of every newspaper.

This guide gives you a region-wise list of 30+ straits, a full section on India’s own straits and channels, a table of mistakes that trip up well-prepared candidates, and practice questions. Short on time? Start with the box below.

What Is A Strait?

Think of a strait as a doorway between two rooms. The rooms are seas or oceans; the walls on either side are land. Whoever controls the doorway controls a lot of traffic, which is why navies, shipping companies and energy ministries watch these places so closely.

Straits form in a few ways:

Tectonic movement: Gibraltar sits where the African and Eurasian plates meet.
Rising sea levels: After the last Ice Age, water flooded low land bridges. The Bering Strait was once Beringia, a land bridge that early humans are believed to have crossed into the Americas.
Erosion and glaciation: Moving water and retreating glaciers carved narrow channels that later filled with sea water.

Strait vs Channel vs Passage vs Gulf vs Canal

Term	What it is	Examples
Strait	Natural, narrow waterway between two landmasses connecting two water bodies	Hormuz, Malacca
Channel	Usually wider; can be a navigable route within a water body or between islands	English Channel, Ten Degree Channel
Passage	A route through open or island-dotted water, often polar	Drake Passage, Duncan Passage
Gulf	A large body of water partly enclosed by land, not a connector	Persian Gulf, Gulf of Mexico
Canal	Man-made	Suez, Panama

Exam Note: Suez and Panama are canals, not straits. A favourite Prelims trap is listing them among straits. In practice, the words “strait”, “channel” and “passage” are used loosely, so questions usually test the name and location, not the label.

One more distinction: a chokepoint is a strategic bottleneck. Many chokepoints are straits (Hormuz, Malacca), but the Suez Canal is a chokepoint too. In March 2021 a single ship, the Ever Given, blocked Suez for about six days and held up a large share of the world’s trade.

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Important Straits of the World

Asia and the Indian Ocean:

Strait	Connects	Separates	Key fact
Malacca	Andaman Sea – South China Sea	Malay Peninsula & Sumatra	Busiest shipping lane
Sunda	Java Sea – Indian Ocean	Java & Sumatra	Krakatoa lies here
Lombok	Java Sea – Indian Ocean	Bali & Lombok	Deep-water alternative to Malacca
Makassar	Celebes Sea – Java Sea	Borneo & Sulawesi	Deep, used by large ships
Palk	Bay of Bengal – Palk Bay	India & Sri Lanka	Shallow; Ram Setu
Ten Degree Channel	Andaman Sea – Bay of Bengal	Little Andaman & Car Nicobar	Splits Andaman from Nicobar
Taiwan	East China Sea – South China Sea	Taiwan & mainland China	Geopolitical flashpoint
Luzon	South China Sea – Philippine Sea	Taiwan & Luzon (Philippines)	Link between South China Sea and the Pacific
Korea (Tsushima)	East China Sea – Sea of Japan	South Korea & Japan	Heavy shipping
Tsugaru	Sea of Japan – Pacific	Honshu & Hokkaido	Seikan rail tunnel beneath it
Tartary	Sea of Japan – Sea of Okhotsk	Sakhalin & mainland Russia	Freezes in winter
Bering	Bering Sea – Chukchi Sea	Russia & Alaska	Diomede Islands; Date Line

Middle East and Africa:

Strait	Connects	Separates	Key fact
Hormuz	Persian Gulf – Gulf of Oman	Iran & Oman	Oil and LNG chokepoint
Bab-el-Mandeb	Red Sea – Gulf of Aden	Yemen & Djibouti/Eritrea	“Gate of Grief”; Perim Island in the middle
Tiran	Gulf of Aqaba – Red Sea	Sinai (Egypt) & Arabia	Its closure to Israeli shipping in 1967 helped trigger the Six-Day War
Mozambique Channel	Western Indian Ocean	Mozambique & Madagascar	Often listed as the longest strait

Europe:

Strait	Connects	Separates	Key fact
Gibraltar	Atlantic – Mediterranean	Spain & Morocco	About 14 km at its narrowest; Pillars of Hercules
Bosphorus	Black Sea – Sea of Marmara	European & Asian Türkiye	Istanbul sits on it
Dardanelles	Aegean Sea – Sea of Marmara	European & Asian Türkiye	Site of the 1915 Gallipoli campaign
Dover	North Sea – English Channel	England & France	Channel Tunnel runs beneath
Messina	Tyrrhenian Sea – Ionian Sea	Sicily & mainland Italy	Whirlpool legends of Scylla and Charybdis
Otranto	Adriatic Sea – Ionian Sea	Italy & Albania	Gateway to the Adriatic
Bonifacio	Tyrrhenian Sea – Mediterranean	Corsica & Sardinia	Treacherous winds
Øresund	Baltic Sea – Kattegat	Denmark & Sweden	Bridge-tunnel link
Kerch	Sea of Azov – Black Sea	Crimea & mainland Russia	Disputed since 2014
Denmark	Arctic Ocean – North Atlantic	Greenland & Iceland	Cold, icy waters

Americas, Oceania and Polar

Strait	Connects	Separates	Key fact
Florida	Gulf of Mexico – Atlantic	Florida & Cuba	Gulf Stream flows through
Yucatán Channel	Caribbean – Gulf of Mexico	Mexico & Cuba	Main entrance to the Gulf of Mexico
Windward Passage	Caribbean – Atlantic	Cuba & Haiti	Key Caribbean route
Davis	Baffin Bay – Labrador Sea	Greenland & Canada	Arctic access
Hudson	Hudson Bay – Labrador Sea	Baffin Island & Quebec	Partly freezes in winter
Magellan	Atlantic – Pacific	Mainland Chile & Tierra del Fuego	Navigated by Magellan in 1520
Drake Passage	South Atlantic – South Pacific	South America & Antarctica	Widest (about 800 km) and roughest
Bass	Tasman Sea – Southern Ocean	Mainland Australia & Tasmania	Notoriously rough
Cook	Tasman Sea – South Pacific	North & South Islands, New Zealand	Strong, unpredictable currents
Torres	Coral Sea – Arafura Sea	Australia & Papua New Guinea	Dotted with small islands

Exam Note: Most questions come in two forms: “Which strait separates X and Y?” and “Which water bodies does X connect?” Practise both directions. For the table above, cover two columns and recall the third.

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Straits of India and the Indian Ocean Region

India has just one true international strait on its doorstep, but a chain of island channels that matter far more strategically than their size suggests.

Palk Strait: India and Sri Lanka

Palk Strait runs between Tamil Nadu and Sri Lanka’s Northern Province. It’s named after Robert Palk, a Governor of Madras in the 1760s. It’s very shallow, often under 10 metres, so big ships can’t use it. Only fishing boats and small craft pass.

Three things make it exam-rich:

Ram Setu (Adam’s Bridge): a chain of limestone shoals between Pamban Island (Rameswaram) and Mannar Island. Palk Bay lies to its north and the Gulf of Mannar to its south.
Sethusamudram Ship Canal: a long-proposed project to dredge a channel through the shoals so ships needn’t go around Sri Lanka. It stalled amid environmental, economic and religious objections.
The New Pamban Bridge: opened in April 2025, it replaced the 1914 rail bridge and is India’s first vertical-lift railway sea bridge.

Then there’s the human side. Katchatheevu, a small island in the strait, was ceded to Sri Lanka under the 1974 maritime boundary agreement. Tamil Nadu fishermen still cross the boundary chasing catch, and arrests by the Sri Lankan Navy keep this a live diplomatic issue.

Exam Note: Palk Strait = India–Sri Lanka. Palk Bay is north of Ram Setu; the Gulf of Mannar is south. Sources differ on which water body a question calls the “other end”, so check your textbook’s wording.

India’s island channels

Channel	Separates	Location
Coco Channel	Coco Islands (Myanmar) & Landfall Island (North Andaman)	Northern Andaman
Duncan Passage	South Andaman & Little Andaman	Andaman
Ten Degree Channel	Little Andaman & Car Nicobar (Andaman from Nicobar)	About 10°N; roughly 150 km wide
Great Channel	Great Nicobar & Sumatra (Indonesia)	Southern tip near Indira Point
Nine Degree Channel	Minicoy & the rest of Lakshadweep	About 9°N
Eight Degree Channel	Minicoy (India) & Maldives	About 8°N

Exam Note: Mnemonic for the north-to-south Andaman chain: Coco, Duncan, Ten, Great. The Ten Degree Channel is the most asked: it divides Andaman from Nicobar. Nine vs Eight Degree is the Lakshadweep trap: Nine splits Minicoy from the other Lakshadweep islands; Eight separates Minicoy from the Maldives. Confirm against your atlas, since some pages mix them up.

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Strategic Importance: Trade, Energy and Dependency

Strait	What flows	Alternative route	India’s exposure
Hormuz	Oil and LNG from the Gulf	Pipelines (Saudi East-West to Yanbu; UAE to Fujairah), partial only	Major source of crude, LPG and LNG
Malacca	Gulf and African energy to East Asia; Asian goods to Europe	Lombok, Sunda (longer)	East Asia trade; A&N Islands’ strategic leverage
Bab-el-Mandeb / Suez	Asia–Europe containers; Gulf oil to Europe	Cape of Good Hope (longer, costlier)	Exports to Europe; freight and insurance costs
Gibraltar	Atlantic–Mediterranean traffic	None for the Mediterranean	End of the Europe route via Suez
Turkish Straits	Black Sea grain, oil, fertiliser	Limited rail and land routes	Black Sea edible oil, grain and fertiliser
Taiwan Strait	Electronics, chips, container traffic	Route east of Taiwan	Electronics supply chains

Common Mistakes and Exam Traps

The trap	The correct take
“Messina is the narrowest international strait”	The Bosphorus is narrower, at roughly 700 m in places; Messina is about 3 km
Malacca vs Hormuz	Malacca = busiest by traffic; Hormuz = most critical for oil
Suez or Panama as straits	They’re man-made canals
Nine Degree vs Eight Degree Channel	Nine: Minicoy from rest of Lakshadweep. Eight: Minicoy from the Maldives
Hudson Strait	Separates Baffin Island and Quebec (Canada), not Labrador
One oil share figure for Hormuz	Sources quote about 20% to 25%; cite the source and year
Palk Strait’s water bodies	Check your textbook: Palk Bay and the Bay of Bengal, with the Gulf of Mannar to the south of Ram Setu

Superlatives at a Glance

Widest: Drake Passage, about 800 km, also among the roughest waters on Earth.
Narrowest in navigation use: the Bosphorus, at roughly 700 m in places.
Often listed as longest: Mozambique Channel.
Busiest (standard exam answer): Malacca. The Dover Strait also claims the title when counting vessels, so read the question wording.
Oil chokepoint: Hormuz.

Previous Year Questions (PYQ) - MCQs

1. UPSC Prelims 2026
Ships from which of the following countries have to cross the Strait of Hormuz to reach the Indian Ocean? 1. Bahrain 2. Syria 3. Qatar 4. Egypt
(a) 1 and 2
(b) 1 and 3
(c) 2 and 3
(d) 3 and 4

Answer: (b). The answer is 1 and 3. Bahrain and Qatar sit on the Persian Gulf. Syria and Egypt don’t.

2. UPSC Prelims 2011
Between India and East Asia, navigation time and distance can be greatly reduced by: 1. Deepening the Malacca Straits between Malaysia and Indonesia. 2. Opening a new canal across the Kra Isthmus between the Gulf of Siam and the Andaman Sea.
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2

Answer: (b). The Kra Isthmus canal would cut the distance, but deepening Malacca would not.

3. UPSC Prelims 2010
Which one of the following can one come across if one travels through the Strait of Malacca?
(a) Bali
(b) Brunei
(c) Java
(d) Singapore

Answer: (d). Singapore is the answer.

4. UPSC Prelims 2008
Which one of the following straits is nearest to the International Date Line?
(a) Malacca Strait
(b) Bering Strait
(c) Strait of Florida
(d) Strait of Gibraltar

Answer: (b). The Bering Strait is the answer.

5. SSC MTS
Which water bodies does the Bab-el-Mandeb strait connect?
(a) Persian Gulf and Gulf of Oman
(b) Baffin Bay and Labrador Sea
(c) Red Sea and Gulf of Aden
(d) Black Sea and Sea of Azov

Answer: (c). The question and its options are listed at the source. The answer follows from the geography.

6. SSC MTS
India is separated from Sri Lanka by ______.
(a) Palk Strait
(b) 9° Channel
(c) 10° Channel
(d) Dover Strait

Answer: (a). The question and options are listed at the source. The answer follows from the geography.

7. SSC MTS 2022
Andaman Islands and Nicobar Islands are separated by a water body called ______.
(a) Palk Strait
(b) Conolly Canal
(c) Ten Degree Channel
(d) Gulf of Mannar

Answer: (c). The source confirms it is the Ten Degree Channel.

8. SSC CHSL 2020
Which channel or strait lies between Great Nicobar Island and Indonesia’s Sumatra Island?
(a) Grand (Great) Channel
(b) 10 Degree Channel
(c) 9 Degree Channel
(d) Palk Strait

Answer: (a). The source gives the answer as the Grand Channel, which lies between Great Nicobar and Sumatra.

9. Delhi Police Constable
Which two island groups does the Ten Degree Channel separate?
(a) India and Sri Lanka
(b) Andaman and Nicobar Islands
(c) Minicoy and Maldives
(d) Lakshadweep and Maldives

Answer: (b). The channel lies at about 10°N and is roughly 150 km wide. Options (c) and (d) are the Eight Degree Channel trap.

10. Consider the statements:
(1) Suez is a strait.
(2) Bab-el-Mandeb links the Red Sea with the Gulf of Aden.
Which is correct?
Answer: only 2. Suez is a canal.

Supreme Court of India — the complete UPSC/SSC notes.

Conclusion

Straits look like simple geography, but they sit where three things meet: static GK, strategic thinking and the news. The same Palk Strait that gives you a one-line SSC answer also carries the Katchatheevu fishermen issue and the Ram Setu debate. The same Hormuz that appears in a Prelims map question is the one choking India’s LPG supply in 2026.

So don’t just memorise the list. Learn each strait in layers:

Where it is: what it connects and what it separates.
Why it matters: the trade, energy or strategic role.
What it means for India: import dependence, the Andaman & Nicobar position, naval reach.

If you do that, the one-liners, the match-the-following questions on Malacca or Hormuz all become variations of the same knowledge.

FAQs

Which is the busiest strait in the world?
Malacca is the standard exam answer, linking the Indian and Pacific oceans through Southeast Asia.

Which strait separates India and Sri Lanka?
The Palk Strait.

What is the Ten Degree Channel?
It separates the Andaman Islands from the Nicobar Islands, around 10°N.

Which strait is the most important for oil?
Hormuz, which carries roughly a fifth of world oil consumption in normal times.

What’s the difference between a strait and a channel?
A strait is a natural narrow link between two water bodies. A channel is usually wider and the term is used more loosely.

Which is the widest strait?
The Drake Passage, at about 800 km.

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Friday, October 30, 2026