Important Straits, Canals and Gulfs of the World: GK Notes
Notes on the world's important straits, channels, ship canals, gulfs and bays: what each joins, what it separates, and the trade chokepoints exams ask about.
By GK24 Editorial Team· Published · 5 min read

A strait is a narrow stretch of water joining two larger water bodies and, in doing so, separating two land masses. A ship canal is the same link cut by human hands across an isthmus. A gulf is a deep inlet of the sea with a comparatively narrow mouth, and a bay is a wider, shallower indentation of the coast. Together these features carry most of the world's seaborne trade, which is why a handful of them are called chokepoints, and why every examination from the SSC papers to the state services asks what a particular strait joins or which two countries it separates. The whole chapter is a set of pairs, and the way to learn it is pair by pair.
Straits of Asia and the Indian Ocean
| Strait or channel | Separates | Joins |
|---|---|---|
| Palk Strait | India and Sri Lanka | Palk Bay and the Gulf of Mannar |
| Strait of Malacca | Malay Peninsula and Sumatra | Andaman Sea and the South China Sea |
| Sunda Strait | Java and Sumatra | Java Sea and the Indian Ocean |
| Strait of Hormuz | Iran and Oman | Persian Gulf and the Gulf of Oman |
| Bab-el-Mandeb | Yemen from Djibouti and Eritrea | Red Sea and the Gulf of Aden |
| Formosa or Taiwan Strait | China and Taiwan | East China Sea and the South China Sea |
| Tsugaru Strait | Honshu and Hokkaido in Japan | Sea of Japan and the Pacific Ocean |
| Makassar Strait | Borneo and Sulawesi | Celebes Sea and the Java Sea |
The Strait of Malacca is the longest strait in the world used for international navigation, running about 800 kilometres beside Singapore, and the Strait of Hormuz is the most watched oil chokepoint on earth.
Straits of Europe, Africa and the Americas
- Strait of Gibraltar separates Spain from Morocco and joins the Atlantic Ocean to the Mediterranean Sea; its headlands are the Pillars of Hercules.
- Bosporus separates European from Asian Turkey and joins the Black Sea to the Sea of Marmara; the Dardanelles joins the Sea of Marmara to the Aegean Sea.
- Strait of Dover, also called Pas de Calais, separates England from France and is the narrowest part of the English Channel, joining it to the North Sea.
- Strait of Messina separates mainland Italy from Sicily, and the Strait of Otranto separates Italy from Albania.
- Mozambique Channel separates Madagascar from mainland Africa and is the longest channel in the world.
- Bering Strait separates Asia from North America, that is Russia from Alaska, and joins the Arctic Ocean to the Bering Sea; the International Date Line runs through it.
- Strait of Magellan separates mainland South America from Tierra del Fuego, while the Drake Passage separates South America from Antarctica.
- Davis Strait separates Greenland from Baffin Island and the Denmark Strait separates Greenland from Iceland.
- Cook Strait separates the North and South Islands of New Zealand, Bass Strait separates Australia from Tasmania, and Torres Strait separates Australia from Papua New Guinea.
Channels around the Indian islands
The island groups of India are cut by channels that are favourite one-mark questions. The Ten Degree Channel separates Little Andaman from Car Nicobar and so divides the Andaman group from the Nicobar group. The Duncan Passage lies between South Andaman and Little Andaman. The Coco Channel separates the Coco Islands of Myanmar from North Andaman. In the Arabian Sea, the Nine Degree Channel separates Minicoy from the rest of the Lakshadweep islands, and the Eight Degree Channel separates Minicoy from the Maldives. Adam's Bridge, the chain of shoals between Rameswaram and Mannar, divides Palk Bay in the north from the Gulf of Mannar in the south.
The great ship canals
| Canal | Country | Joins | Points to remember |
|---|---|---|---|
| Suez Canal | Egypt | Mediterranean Sea and the Red Sea | Opened in 1869; about 193 km; sea level, so it has no locks; nationalised by Egypt in 1956 |
| Panama Canal | Panama | Atlantic Ocean and the Pacific Ocean | Opened in 1914; about 82 km; uses locks and crosses Gatun Lake; handed over by the United States on 31 December 1999 |
| Kiel Canal | Germany | North Sea and the Baltic Sea | Opened in 1895; one of the busiest artificial waterways in the world |
| Grand Canal | China | Beijing and Hangzhou | The longest artificial waterway ever built, begun in ancient times |
| Welland Canal | Canada | Lake Erie and Lake Ontario | Lets ships bypass the Niagara Falls |
| Corinth Canal | Greece | Gulf of Corinth and the Saronic Gulf | Cuts across the Isthmus of Corinth |
The Suez Canal shortens the voyage from Europe to India enormously, because a ship no longer has to round the Cape of Good Hope, and the Panama Canal does the same for the voyage from the Atlantic to the Pacific coast of America by avoiding Cape Horn.
Gulfs and bays
The Gulf of Mexico is the largest gulf in the world and the Bay of Bengal is the largest bay. The Persian Gulf, reached through the Strait of Hormuz, is the most important oil-exporting water body, and the Gulf of Guinea, off West Africa, lies where the Equator meets the Prime Meridian. India has two gulfs on its western coast, the Gulf of Kutch and the Gulf of Khambhat, both in Gujarat, and the Gulf of Mannar in the south, which is a biosphere reserve. The Red Sea ends in two arms, the Gulf of Suez leading to the canal and the Gulf of Aqaba leading to Israel and Jordan. Other gulfs that appear in papers are the Gulf of Aden, the Gulf of Oman, the Gulf of Tonkin, the Gulf of Thailand, the Gulf of Carpentaria in northern Australia, the Gulf of Alaska, the Gulf of California, the Gulf of St Lawrence, the Gulf of Sidra off Libya, and the Gulf of Finland, the Gulf of Bothnia and the Gulf of Riga in the Baltic Sea.
Exam Point of View
Questions are almost always of the form which strait joins which two water bodies, or which two countries a strait separates, so learn each feature as a pair. The canals are asked by year of opening and by the seas they join, and the Suez and Panama canals are compared on the single point of locks. Traps include swapping the Bosporus with the Dardanelles, confusing the Ten Degree Channel with the Nine Degree Channel, placing the Palk Strait between India and the Maldives, and answering that the Suez Canal has locks when in fact it is a sea-level canal.
Important Facts
| Palk Strait | Between India and Sri Lanka; joins Palk Bay and the Gulf of Mannar |
|---|---|
| Strait of Malacca | Between the Malay Peninsula and Sumatra; longest strait used for international navigation |
| Strait of Hormuz | Between Iran and Oman; joins the Persian Gulf and the Gulf of Oman |
| Bab-el-Mandeb | Joins the Red Sea and the Gulf of Aden |
| Strait of Gibraltar | Between Spain and Morocco; joins the Atlantic Ocean and the Mediterranean Sea |
| Bering Strait | Between Russia and Alaska; separates Asia from North America |
| Suez Canal | Egypt, 1869, about 193 km, no locks, Mediterranean to Red Sea |
| Panama Canal | Panama, 1914, about 82 km, with locks and Gatun Lake, Atlantic to Pacific |
| Kiel Canal | Germany, 1895; joins the North Sea and the Baltic Sea |
| Ten Degree Channel | Between Little Andaman and Car Nicobar |
| Largest gulf and bay | Gulf of Mexico and the Bay of Bengal |
| Gulfs of India | Gulf of Kutch and Gulf of Khambhat in Gujarat, Gulf of Mannar in the south |
Practice MCQs on this topic
The Palk Strait lies between which two countries?
- A.India and Myanmar
- B.India and Sri Lanka
- C.India and the Maldives
- D.India and Indonesia
Show answer
Explanation
The correct answer is B, India and Sri Lanka. The Palk Strait lies between the Ramanathapuram coast of Tamil Nadu and the Jaffna region of northern Sri Lanka, and it joins Palk Bay in the north with the Gulf of Mannar in the south; the shoals of Adam's Bridge run across its southern end. A is wrong because India and Myanmar are separated in the sea by the Coco Channel near North Andaman and share a land boundary in the north-east, not a strait in the south. C is wrong because the Maldives lie far out in the Arabian Sea and are separated from Minicoy of Lakshadweep by the Eight Degree Channel. D is wrong because Indonesia is separated from the Indian islands by a wide stretch of the Andaman Sea, the nearest Indonesian point to India being Sumatra off Great Nicobar.
The Strait of Hormuz connects the Persian Gulf with which water body?
- A.The Red Sea
- B.The Gulf of Aden
- C.The Gulf of Oman
- D.The Mediterranean Sea
Show answer
Explanation
The correct answer is C, the Gulf of Oman. The Strait of Hormuz runs between the Iranian coast and the Musandam peninsula of Oman and is the only sea route out of the Persian Gulf, leading into the Gulf of Oman and from there into the Arabian Sea; that is why it is the world's most sensitive oil chokepoint. A is wrong because the Red Sea lies on the other side of the Arabian peninsula and is reached from the Indian Ocean through Bab-el-Mandeb. B is wrong because the Gulf of Aden lies off Yemen and Somalia and is joined to the Red Sea, not to the Persian Gulf. D is wrong because the Mediterranean Sea is linked to the Red Sea by the Suez Canal and to the Atlantic by the Strait of Gibraltar, and has no direct opening into the Persian Gulf.
The Suez Canal connects which two water bodies?
- A.The Mediterranean Sea and the Red Sea
- B.The Atlantic Ocean and the Pacific Ocean
- C.The North Sea and the Baltic Sea
- D.The Black Sea and the Aegean Sea
Show answer
Explanation
The correct answer is A, the Mediterranean Sea and the Red Sea. The Suez Canal, opened in 1869, runs about 193 kilometres across the Isthmus of Suez in Egypt from Port Said on the Mediterranean to the city of Suez on the Red Sea, and because the two seas stand at nearly the same level the canal needs no locks. B is wrong because the Atlantic and the Pacific are joined by the Panama Canal across the Isthmus of Panama. C is wrong because the North Sea and the Baltic are joined by the Kiel Canal in Germany, opened in 1895. D is wrong because the Black Sea reaches the Aegean through the Bosporus, the Sea of Marmara and the Dardanelles, a natural chain of straits in Turkey and not a canal at all.
Which lake do ships cross while passing through the Panama Canal?
- A.Lake Maracaibo
- B.Lake Titicaca
- C.Gatun Lake
- D.Lake Nicaragua
Show answer
Explanation
The correct answer is C, Gatun Lake. The Panama Canal does not cut through at sea level; ships are lifted by locks into the artificial Gatun Lake, sail across it and through the Culebra or Gaillard Cut, and are then lowered by locks on the other side, which is why the canal needs a large freshwater reservoir. A is wrong because Lake Maracaibo is in Venezuela, an inlet of the Caribbean and not part of any canal. B is wrong because Lake Titicaca lies high in the Andes on the border of Peru and Bolivia and is the highest navigable lake in the world, far from Panama. D is wrong because Lake Nicaragua was considered for a rival canal route in the nineteenth century, and a Nicaraguan canal has been proposed many times, but no such canal carries shipping today.
The Bering Strait separates which two continents?
- A.Asia and North America
- B.Europe and Africa
- C.Asia and Europe
- D.South America and Antarctica
Show answer
Explanation
The correct answer is A, Asia and North America. The Bering Strait lies between the Chukchi peninsula of Russia and the Seward peninsula of Alaska, joining the Arctic Ocean to the Bering Sea, and the International Date Line passes through it; in the ice ages a land bridge here allowed people and animals to cross into America. B is wrong because Europe and Africa are separated by the Strait of Gibraltar, between Spain and Morocco. C is wrong because Asia and Europe meet on land along the Urals and are divided at sea by the Bosporus and the Dardanelles in Turkey. D is wrong because South America is separated from Antarctica by the Drake Passage, the stormy stretch of water south of Cape Horn. Remember also that the strait is only about 82 kilometres wide and that Russia and the United States face each other across it at the Diomede Islands, where the date line makes one island a day ahead of the other.
The Strait of Gibraltar separates which two countries?
- A.Italy and Tunisia
- B.Spain and Morocco
- C.France and England
- D.Greece and Turkey
Show answer
Explanation
The correct answer is B, Spain and Morocco. The Strait of Gibraltar is the narrow entrance to the Mediterranean from the Atlantic Ocean, with the Rock of Gibraltar on the European side and Jebel Musa on the African side; the two headlands were known to the ancients as the Pillars of Hercules. A is wrong because Italy and Tunisia face each other across the Strait of Sicily, a much wider stretch of the Mediterranean. C is wrong because France and England are separated by the Strait of Dover, also called Pas de Calais, the narrowest part of the English Channel. D is wrong because Greece and Turkey face each other across the Aegean Sea and its many islands, while the straits of Turkey, the Bosporus and the Dardanelles, lie wholly within Turkey.
The Bab-el-Mandeb strait connects the Red Sea with
- A.the Gulf of Aden
- B.the Persian Gulf
- C.the Gulf of Aqaba
- D.the Mediterranean Sea
Show answer
Explanation
The correct answer is A, the Gulf of Aden. Bab-el-Mandeb, the Gate of Tears, lies between Yemen on the Asian side and Djibouti and Eritrea on the African side, and it is the southern doorway of the Red Sea, opening into the Gulf of Aden and then the Arabian Sea; every ship using the Suez Canal on the India-Europe route passes through it. B is wrong because the Persian Gulf is entered from the Gulf of Oman through the Strait of Hormuz. C is wrong because the Gulf of Aqaba is one of the two northern arms of the Red Sea itself, leading to Jordan and Israel, and is not reached through Bab-el-Mandeb. D is wrong because the Red Sea is joined to the Mediterranean at its northern end by the Suez Canal, a man-made waterway and not a strait.
The Ten Degree Channel separates which two islands?
- A.South Andaman and Little Andaman
- B.Little Andaman and Car Nicobar
- C.Minicoy and the Maldives
- D.Great Nicobar and Sumatra
Show answer
Explanation
The correct answer is B, Little Andaman and Car Nicobar. The Ten Degree Channel takes its name from the parallel of ten degrees north that runs along it, and it divides the Andaman group of islands from the Nicobar group, lying between Little Andaman in the north and Car Nicobar in the south. A is wrong because South Andaman and Little Andaman are separated by the Duncan Passage, a narrower gap within the Andaman group. C is wrong because Minicoy is separated from the Maldives by the Eight Degree Channel, and from the rest of Lakshadweep by the Nine Degree Channel. D is wrong because Great Nicobar is separated from Sumatra in Indonesia by the Great Channel, the stretch of water that makes Indonesia India's nearest maritime neighbour in the south-east.
The Mozambique Channel lies between the African mainland and which island?
- A.Mauritius
- B.Sri Lanka
- C.Madagascar
- D.Seychelles
Show answer
Explanation
The correct answer is C, Madagascar. The Mozambique Channel is the stretch of the Indian Ocean between Mozambique on the African mainland and the island of Madagascar, and at roughly 1,600 kilometres in length it is counted as the longest channel in the world; the Comoros lie at its northern mouth. A is wrong because Mauritius lies well to the east of Madagascar in the open Indian Ocean and has no channel named after it. B is wrong because Sri Lanka is separated from India by the Palk Strait and the Gulf of Mannar, thousands of kilometres from Africa. D is wrong because the Seychelles is a scattered group of islands north-east of Madagascar, again in open ocean rather than in a narrow channel. Examiners also pair the channel with the Comoros and with the Mozambique Current that flows through it, so the name should bring to mind Africa on one side and Madagascar on the other.
Which is the largest gulf in the world?
- A.The Persian Gulf
- B.The Gulf of Mexico
- C.The Gulf of Guinea
- D.The Gulf of Carpentaria
Show answer
Explanation
The correct answer is B, the Gulf of Mexico. Enclosed by the United States, Mexico and the island of Cuba, the Gulf of Mexico is the largest gulf on earth, and it is the nursery of the hurricanes that strike the American coast as well as the home of the warm Gulf Stream. A is wrong because the Persian Gulf, though the most important for oil, is far smaller and shallower, and is counted among the shallow marginal seas. C is wrong because the Gulf of Guinea, off the coast of West Africa, is famous chiefly for lying where the Equator crosses the Prime Meridian. D is wrong because the Gulf of Carpentaria is a shallow sea indenting the northern coast of Australia and is much smaller than the Gulf of Mexico.
The Kiel Canal of Germany joins the North Sea with which sea?
- A.The Black Sea
- B.The Baltic Sea
- C.The Caspian Sea
- D.The Adriatic Sea
Show answer
Explanation
The correct answer is B, the Baltic Sea. The Kiel Canal, opened in 1895, cuts across the base of the Jutland peninsula in northern Germany and lets ships pass from the North Sea to the Baltic without sailing round Denmark; it is one of the busiest artificial waterways in the world. A is wrong because the Black Sea is reached from the Mediterranean through the Turkish straits and has no canal to the North Sea. C is wrong because the Caspian Sea is landlocked and is linked to the Black Sea and the Baltic only through the Russian river and canal system, such as the Volga-Don Canal. D is wrong because the Adriatic Sea is an arm of the Mediterranean between Italy and the Balkans and is nowhere near the German canal.
Frequently Asked Questions
Which strait separates India from Sri Lanka?
The Palk Strait. It lies between Tamil Nadu and northern Sri Lanka and joins Palk Bay in the north to the Gulf of Mannar in the south. The chain of shoals called Adam's Bridge or Ram Setu runs across it between Rameswaram and Mannar island.
Why does the Suez Canal have no locks while the Panama Canal has them?
The Suez Canal runs across level desert between two seas at nearly the same level, so water can flow through it freely. The Panama Canal has to lift ships over the hilly isthmus and across Gatun Lake, about 26 metres above sea level, so locks are needed to raise and lower them.
Which strait is called the world's most important oil chokepoint?
The Strait of Hormuz, between Iran and the Musandam peninsula of Oman, which joins the Persian Gulf to the Gulf of Oman. A very large share of the oil exported by sea passes through it, which is why any tension there affects world oil prices at once.
What is the difference between a gulf and a bay?
A gulf is a deep inlet of the sea almost surrounded by land, with a comparatively narrow entrance, such as the Persian Gulf. A bay is a wider and usually shallower curve of the coastline with a broad mouth, such as the Bay of Bengal. The distinction is one of shape, not of size.
Which channel separates the Andaman Islands from the Nicobar Islands?
The Ten Degree Channel, which lies between Little Andaman and Car Nicobar and takes its name from the ten degree north parallel running through it. It is about 150 kilometres wide and carries heavy shipping traffic.
Sources
- Fundamentals of Physical Geography (Class XI), chapters on oceans and water bodies — NCERT
- The National Atlas of India — National Atlas and Thematic Mapping Organisation, Government of India
- India Yearbook, chapter on land and the people — Publications Division, Government of India





