50 Fun Facts About Seas of the World

Which body of water, whose shores are the lowest dry land on Earth, lets bathers float with ease?

The Dead Sea is almost ten times as salty as the ocean, which makes its water so dense that swimming feels like floating. Its surface lies about 440 metres below sea level.

Which sea, bounded by four Atlantic currents rather than by land, is the only one with no coastline?

The Sargasso Sea is marked out by its mats of brown Sargassum seaweed and calm blue water. European eels hatch there, then travel all the way to Europe as they grow.

Which sea, bordered by Iran, Kazakhstan and Azerbaijan, is often listed as the world's largest lake?

The Caspian Sea covers an area larger than Germany and holds roughly 40% of all the world's lake water. Its sturgeon produce the roe behind its famous caviar.

Which Central Asian sea mostly dried up after Soviet irrigation diverted the rivers that fed it?

The Aral Sea was once among the world's largest lakes, but by 2007 it had shrunk to a tenth of its former size. Its eastern basin is now called the Aralkum Desert.

Which sea bordering Turkey and Ukraine has oxygen-free depths that preserve ancient shipwrecks?

The Black Sea is more than 90% oxygen-free in its depths, because its deep water never mixes with the surface. Byzantine ships have been found there in excellent condition.

Which sea between Britain and Norway covers Doggerland, a plain where Stone Age hunters once lived?

The North Sea swallowed Doggerland between 10,000 and 7,000 years ago as melting ice raised the oceans. Fishing boats there still drag up mammoth remains and prehistoric tools.

Which sea between Alaska and Asia is fished for king crab on the TV series Deadliest Catch?

The Bering Sea covers a drowned land bridge that most scientists think the first humans crossed into the Americas. It takes its name from a Danish-born navigator who explored it in 1728.

Which sea off Queensland named a 1942 battle in which the rival fleets never saw each other?

The Coral Sea holds the Great Barrier Reef, the largest reef system on Earth. In the 1942 battle, American and Japanese carriers struck from over the horizon using aircraft alone.

Which sea, nicknamed "the Ditch" by people on both shores, separates Australia from New Zealand?

The Tasman Sea is about 2,000 km wide, and it takes its name from the Dutch explorer who in 1642 became the first European known to cross it.

Which stretch of water, just 14 km wide at its narrowest, separates Europe from Africa?

The Strait of Gibraltar is flanked by the heights the ancients called the Pillars of Hercules, which gave the strait its Latin name, Fretum Herculeum.

Which sea between Africa and Saudi Arabia is lined with resorts such as Egypt's Sharm El Sheikh?

The Red Sea is one of the warmest and saltiest seas in the world, because no major river feeds it and evaporation is intense.

Which sea, once the haunt of the pirate Blackbeard, washes Jamaica, Aruba and the coast of Colombia?

The Caribbean Sea reaches its deepest point, about 7,686 metres down, in the Cayman Trough between Jamaica and the Cayman Islands.

Which sea, enclosed by Sweden, Finland and Poland, is famed for the amber found along its shores?

The Baltic Sea is the world's largest basin of brackish water, too fresh for the shipworm, so old wooden wrecks such as the warship Vasa stay well preserved.

Which sea between Vietnam and the Philippines holds the disputed Spratly and Paracel islands?

The South China Sea carried $3.4 trillion of the world's $16 trillion in shipping trade in 2016, about a fifth of the total. Several countries claim its hundreds of islets and reefs.

Which sea lies between India and Oman, with Pakistan's port of Karachi on its northern shore?

The Arabian Sea has carried trade since the region's first international networks formed in the 3rd millennium BC. Its sailors long had to time their voyages around the monsoon winds.

Which sea between Greece and Turkey is dotted with islands such as Rhodes, Naxos and Lesbos?

The Aegean Sea was once known simply as the Archipelago, which is how that word came to mean any sea scattered with islands.

Which sea separates Italy from the Balkan Peninsula, with Venice at its northern end?

The Adriatic Sea holds more than 1,300 islands and islets, nearly all of them strung along its eastern shore in Croatia.

Which sea surrounds the Isle of Man and has Anglesey, off north Wales, as its largest island?

The Irish Sea separates Great Britain from its western neighbour, and the Isle of Man in the middle of it is a self-governing Crown Dependency.

Which lock-free waterway, opened in 1869, lets Mediterranean ships reach Asia without rounding Africa?

The Suez Canal needs no locks because the land is flat and the sea stands at almost the same level at each end. An earlier plan was dropped over a mistaken belief that one end was 8.5 metres higher.

Which river, in which the Bible says Jesus was baptised, flows through the Sea of Galilee?

The Jordan flows from north to south, and the Sea of Galilee it passes through is the lowest freshwater lake on Earth, more than 200 metres below sea level.

Which sea does South Korea want the world to call the East Sea, in a dispute dating from 1992?

The Sea of Japan has almost no tides, because it is so nearly cut off from the Pacific. North Korea prefers a third name for it, the Korean East Sea.

Which sea west of the Korean Peninsula is named for the silt that great rivers pour into it?

The Yellow Sea receives so much sand and silt from rivers such as the Yellow River that its water turns a golden colour.

Which small inland sea lies entirely within Turkey, between the country's European and Asian shores?

The Sea of Marmara is named after its largest island, itself named for the marble found there. At about 11,350 square kilometres, it is often called the smallest sea in the world.

Which waterway through Istanbul is the world's narrowest strait open to international shipping?

The Bosporus narrows to just 700 metres, and three bridges and two tunnels now join the European and Asian halves of the city across it.

Which river burst through an irrigation canal in 1905 and accidentally created the Salton Sea?

The Colorado poured through a broken canal gate for two years before repairs were finished. The Salton Sea it left behind is now California's largest lake.

Which country's Sea of Cortez separates a long desert peninsula from the mainland's Pacific coast?

Mexico's Sea of Cortez, also called the Gulf of California, is thought to be one of the most ecologically diverse seas on Earth. Parts of it are a UNESCO World Heritage Site.

Which chasm on the edge of the Philippine Sea holds the deepest known point in any ocean?

The Mariana Trench plunges to about 10,935 metres in the Challenger Deep. That puts its floor more than 2 km farther from sea level than the summit of Mount Everest.

Which country's waters include the Java, Banda and Flores seas, set among thousands of islands?

Indonesia is the world's largest archipelagic state, with between 13,000 and 17,000 islands. The Java Sea at its heart is shallow, averaging just 46 metres deep.

Which country's Arctic coast is washed by the White, Kara and Laptev seas?

Russia holds the whole of the White Sea as internal waters, while the Kara and Laptev seas lie off the northern coast of Siberia.

Which polar sea crushed Ernest Shackleton's ship Endurance, whose wreck was found in 2022?

The Weddell Sea has been judged by scientists to have the clearest water of any sea. Shackleton's crew spent about 15 months trapped in its pack ice before escaping by lifeboat to Elephant Island.

Which sea lies between mainland Italy, Sardinia and Corsica, with Naples as a main port?

The Tyrrhenian Sea sits near the meeting point of the African and Eurasian plates, so volcanoes rise from its floor and from islands such as Stromboli.

Which Arctic sea off northern Norway was the scene of the Kursk submarine disaster in August 2000?

The Barents Sea is named after Willem Barentsz, a Dutch navigator who died in 1597 on his third voyage in search of a sea route over the top of Asia.

Which sea, once known as the Burma Sea, lies off the west coast of Thailand and the Malay Peninsula?

The Andaman Sea is cut off from the Bay of Bengal by two island chains, the Andamans and the Nicobars. Its fishing and tourist towns were badly damaged by the tsunami of December 2004.

Which Arctic sea north of Alaska is named after the hydrographer who devised the wind force scale?

The Beaufort Sea honours Sir Francis Beaufort, the naval officer who created both the wind scale and a cipher. Its waters stay frozen over for most of the year.

Which volcanic land in Asia's far east forms the eastern shore of the Sea of Okhotsk?

Kamchatka is a peninsula whose volcanoes are a UNESCO World Heritage Site and part of the Pacific Ring of Fire. One of the world's deepest ocean trenches runs just off its other coast.

What did the ancient Romans mean by Mare Nostrum, their proud name for the whole Mediterranean?

Our Sea was no idle boast: Rome remains the only state in history to have controlled the entire Mediterranean coast.

Which strait, known in antiquity as the Hellespont, runs past the Gallipoli peninsula in Turkey?

The Dardanelles is where the Persian king Xerxes is said to have built pontoon bridges for his army, and where Lord Byron swam from Europe to Asia in 1810.

Which sea route through Canada's Arctic islands was first sailed end to end by Roald Amundsen?

The Northwest Passage links the Atlantic and the Pacific across the top of North America. Amundsen's first complete crossing by ship took from 1903 to 1906.

Which Italian port, birthplace of Christopher Columbus, is the main city on the Ligurian Sea?

Genoa has been one of the Mediterranean's most important ports for centuries, and its sea is thought to be named after the ancient Ligures people.

Which sea lane between Sumatra and Malaysia is the main link from the Indian Ocean to the Pacific?

The Strait of Malacca saw more than 94,000 ships pass through in 2008, traffic so heavy that piracy and smuggling have become a modern concern there.

Which body of water, recognised by National Geographic only in 2021, includes the Amundsen Sea?

The Southern Ocean is geologically the youngest of the oceans, formed roughly 30 million years ago when Antarctica and South America drifted apart.

Which island, the largest in the Mediterranean, is cut off from Italy by the Strait of Messina?

Sicily is crowned by Mount Etna, the tallest active volcano in Europe. The strait dividing it from the mainland is only about 3 km wide at its northern end.

Which vast island, four-fifths covered by an ice sheet, lies across the Labrador Sea from Canada?

Greenland is the world's largest island, and the lowest temperature ever recorded in the Northern Hemisphere, −69.6 °C, was measured near the top of its ice sheet in 1991.

Under UN sea law, what gives a coastal state sole resource rights out to 200 nautical miles?

An exclusive economic zone starts where the 12-nautical-mile territorial sea ends, and it covers resources from fish and oil to energy generated by water and wind.

Which sea, joined to a larger neighbour by the narrow Kerch Strait, is the shallowest in the world?

The Sea of Azov is nowhere more than about 14 metres deep, and the strait at its mouth narrows to only a few kilometres across.

Which sea off the Dutch, German and Danish coasts is Earth's largest unbroken tidal flat system?

The Wadden Sea lies behind the low Frisian Islands and is a vital stop for breeding and migrating birds. Its Dutch and German parts joined the World Heritage List in 2009.

Which sea, a name coined only in 1988, takes in Puget Sound and the Strait of Georgia?

The Salish Sea got its name from Bert Webber, a professor in Bellingham, Washington, who wanted one name for the region's combined waters.

Which term do geographers use for a division of an ocean partly enclosed by islands, archipelagos or peninsulas?

Marginal sea is the textbook label for a division of an ocean hemmed in by islands, archipelagos or peninsulas, sometimes with a submarine ridge marking its outer limit.

Which 1936 agreement, signed in Switzerland, makes warships notify Turkey before using its straits?

The Montreux Convention took effect in November 1936 and settled a long-running dispute over who should control the Turkish straits.

Which sea, the southernmost on Earth, has its southern part covered by the world's largest ice shelf?

The Ross Sea was declared a marine park in 2016, under an agreement signed by 24 countries and the European Union. It is named after James Clark Ross, the British explorer who reached it in 1841.