The Strait of Dover or Dover Strait (french: Pas de Calais - ''Strait of Calais'') is the

strait A strait is an oceanic landform connecting two seas or two other large areas of water. The surface water generally flows at the same elevation on both sides and through the strait in either direction. Most commonly, it is a narrow ocean channe ...

at the narrowest part of the

English Channel The English Channel, "The Sleeve"; nrf, la Maunche, "The Sleeve" (Cotentinais) or ( Jèrriais), (Guernésiais), "The Channel"; br, Mor Breizh, "Sea of Brittany"; cy, Môr Udd, "Lord's Sea"; kw, Mor Bretannek, "British Sea"; nl, Het Kana ...

, marking the boundary between the Channel and the

North Sea The North Sea lies between Great Britain, Norway, Denmark, Germany, the Netherlands and Belgium. An epeiric sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian S ...

, and separating

Great Britain Great Britain is an island in the North Atlantic Ocean off the northwest coast of continental Europe. With an area of , it is the largest of the British Isles, the largest European island and the ninth-largest island in the world. It is ...

from

continental Europe Continental Europe or mainland Europe is the contiguous continent of Europe, excluding its surrounding islands. It can also be referred to ambiguously as the European continent, – which can conversely mean the whole of Europe – and, by ...

. The shortest distance across the strait, at approximately , is from the

South Foreland South Foreland is a chalk headland on the Kent coast of southeast England. It presents a bold cliff to the sea, and commands views over the Strait of Dover. It is centred northeast of Dover and 15 miles south of North Foreland. It includes ...

, northeast of

Dover Dover () is a town and major ferry port in Kent, South East England. It faces France across the Strait of Dover, the narrowest part of the English Channel at from Cap Gris Nez in France. It lies south-east of Canterbury and east of Maidstone ...

in the English county of

Kent Kent is a county in South East England and one of the home counties. It borders Greater London to the north-west, Surrey to the west and East Sussex to the south-west, and Essex to the north across the estuary of the River Thames; it faces ...

, to

Cap Gris Nez Cap Gris-Nez (literally "cape grey nose"; ) is a cape on the Côte d'Opale in the Pas-de-Calais ''département'' in northern France. The 'Cliffs of the Cape' is the closest point of France to England – from their English counterparts at Do ...

, a cape near to

Calais Calais ( , , traditionally , ) is a port city in the Pas-de-Calais department, of which it is a subprefecture. Although Calais is by far the largest city in Pas-de-Calais, the department's prefecture is its third-largest city of Arras. Th ...

in the French

département In the administrative divisions of France, the department (french: département, ) is one of the three levels of government under the national level ("territorial collectivity, territorial collectivities"), between the regions of France, admin ...

Pas-de-Calais Pas-de-Calais (, " strait of Calais"; pcd, Pas-Calés; also nl, Nauw van Kales) is a department in northern France named after the French designation of the Strait of Dover, which it borders. It has the most communes of all the departments ...

. Between these points lies the most popular route for cross-channel swimmers. The entire strait is within the

territorial waters The term territorial waters is sometimes used informally to refer to any area of water over which a sovereign state has jurisdiction, including internal waters, the territorial sea, the contiguous zone, the exclusive economic zone, and potenti ...

of France and the United Kingdom, but a right of

transit passage Transit passage is a concept of the law of the sea, which allows a vessel or aircraft the freedom of navigation or overflight solely for the purpose of continuous and expeditious transit of a strait between one part of the high seas or exclusive ...

under the

United Nations Convention on the Law of the Sea The United Nations Convention on the Law of the Sea (UNCLOS), also called the Law of the Sea Convention or the Law of the Sea Treaty, is an international agreement that establishes a legal framework for all marine and maritime activities. , 167 c ...

allows vessels of other nations to move freely through the strait. On a clear day, it is possible to see the opposite coastline of England from France and vice versa with the naked eye, with the most famous and obvious sight being the

White Cliffs of Dover The White Cliffs of Dover is the region of English coastline facing the Strait of Dover and France. The cliff face, which reaches a height of , owes its striking appearance to its composition of chalk accented by streaks of black flint, deposi ...

from the French coastline and shoreline buildings on both coastlines, as well as lights on either coastline at night, as in

Matthew Arnold Matthew Arnold (24 December 1822 – 15 April 1888) was an English poet and cultural critic who worked as an inspector of schools. He was the son of Thomas Arnold, the celebrated headmaster of Rugby School, and brother to both Tom Arnold, lite ...

's poem "

Dover Beach "Dover Beach" is a lyric poem by the English poet Matthew Arnold. It was first published in 1867 in the collection ''New Poems''; however, surviving notes indicate its composition may have begun as early as 1849. The most likely date is 1851.Al ...

Shipping traffic

Most maritime traffic between the Atlantic Ocean and the North Sea and

Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden and the North and Central European Plain. The sea stretches from 53°N to 66°N latitude and from ...

passes through the Strait of Dover, rather than taking the longer and more dangerous route around the north of Scotland. The strait is one of the busiest

international seaways International is an adjective (also used as a noun) meaning "between nations". International may also refer to: Music Albums * ''International'' (Kevin Michael album), 2011 * ''International'' (New Order album), 2002 * ''International'' (The T ...

in the world, used by over 400 commercial vessels daily. This has made traffic safety a critical issue, with

HM Coastguard His Majesty's Coastguard (HMCG) is a section of the Maritime and Coastguard Agency responsible, through the Secretary of State for Transport to Parliament, for the initiation and co-ordination of all maritime search and rescue (SAR) within the ...

and the

Maritime Gendarmerie The Maritime Gendarmerie (french: Gendarmerie maritime) is a component of the French National Gendarmerie under operational control of the chief of staff of the French Navy. It employs 1,157 personnel and operates around thirty patrol boats and h ...

maintaining a 24-hour watch over the strait and enforcing a strict regime of

shipping lane A sea lane, sea road or shipping lane is a regularly used navigable route for large water vessels (ships) on wide waterways such as oceans and large lakes, and is preferably safe, direct and economic. During the Age of Sail, they were determined b ...

s. In addition to the intensive north-east to south-west traffic, the strait is crossed from north-west to south-east by

ferries A ferry is a ship, watercraft or amphibious vehicle used to carry passengers, and sometimes vehicles and cargo, across a body of water. A passenger ferry with many stops, such as in Venice, Italy, is sometimes called a water bus or water tax ...

linking

and

Dunkirk Dunkirk (french: Dunkerque ; vls, label=French Flemish, Duunkerke; nl, Duinkerke(n) ; , ;) is a commune in the department of Nord in northern France. Until 1994 these provided the only route across it except for air transport. The

Channel Tunnel The Channel Tunnel (french: Tunnel sous la Manche), also known as the Chunnel, is a railway tunnel that connects Folkestone (Kent, England, UK) with Coquelles ( Hauts-de-France, France) beneath the English Channel at the Strait of Dover. ...

now provides an alternative route, crossing beneath the strait at an average depth of below the seabed. The town of Dover gives its name to one of the sea areas of the British

Shipping Forecast The Shipping Forecast is a BBC Radio broadcast of weather reports and forecasts for the seas around the coasts of the British Isles. It is produced by the Met Office and broadcast by BBC Radio 4 on behalf of the Maritime and Coastguard Agency. ...

Geological formation

The formation of strait was through scouring by

erosion Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is distin ...

. It had for many millennia (since the last warm

interglacial An interglacial period (or alternatively interglacial, interglaciation) is a geological interval of warmer global average temperature lasting thousands of years that separates consecutive glacial periods within an ice age. The current Holocene in ...

) been a land bridge that linked the

Weald The Weald () is an area of South East England between the parallel chalk escarpments of the North and the South Downs. It crosses the counties of Hampshire, Surrey, Sussex and Kent. It has three separate parts: the sandstone "High Weald" in the ...

in Great Britain to the Boulonnais in the

Pas de Calais The Strait of Dover or Dover Strait (french: Pas de Calais - ''Strait of Calais''), is the strait at the narrowest part of the English Channel, marking the boundary between the Channel and the North Sea, separating Great Britain from continent ...

. Though pitted by troughs and rivers, the English Channel was almost mainly land at the height of the last ice age. The predominant geology of both and of the seafloor is

chalk Chalk is a soft, white, porous, sedimentary carbonate rock. It is a form of limestone composed of the mineral calcite and originally formed deep under the sea by the compression of microscopic plankton that had settled to the sea floor. Chalk ...

. Although somewhat resistant to erosion, erosion of both coasts has created the famous

white cliffs of Dover The White Cliffs of Dover is the region of English coastline facing the Strait of Dover and France. The cliff face, which reaches a height of , owes its striking appearance to its composition of chalk accented by streaks of black flint, deposi ...

in the UK and the

Cap Blanc Nez Cap Blanc-Nez (french: kap blɑ̃ ne, literally "Cape White Nose" in English; from Dutch ''Blankenesse'', white headland) is a cape on the Côte d'Opale, in the Pas-de-Calais ''département'', in northern France, culminating at 134 m. The clif ...

in France. The

was bored through solid chalk – compacted remains of sea creatures and marine- deposited, ground up calciferous rock/soil debris. The

Rhine ), Surselva, Graubünden, Switzerland , source1_coordinates= , source1_elevation = , source2 = Rein Posteriur/Hinterrhein , source2_location = Paradies Glacier, Graubünden, Switzerland , source2_coordinates= , so ...

(as the

Urstrom The Urstrom is a geologists' name for a great glacial age river of the Polish and north German plain, which drained the combined melt-waters from the northern headwaters of the Alps and the southern part of the Scandinavian ice during the Devensia ...

) flows northeast into the North Sea as the sea (covering most of the Netherlands) fell during the start of the first of the

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...

Ice Ages An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and gree ...

. The new ice unusually created a dam from

Scandinavia Scandinavia; Sámi languages: /. ( ) is a subregion#Europe, subregion in Northern Europe, with strong historical, cultural, and linguistic ties between its constituent peoples. In English usage, ''Scandinavia'' most commonly refers to Denmark, ...

to Scotland, and the Rhine, combined with the

Thames The River Thames ( ), known alternatively in parts as the River Isis, is a river that flows through southern England including London. At , it is the longest river entirely in England and the second-longest in the United Kingdom, after the R ...

and drainage from much of

north Europe The northern region of Europe has several definitions. A restrictive definition may describe Northern Europe as being roughly north of the southern coast of the Baltic Sea, which is about 54°N, or may be based on other geographical factors ...

, created a vast lake behind the dam, which eventually spilled over the Weald into the English Channel. This overflow followed by further scouring became recognisably the Short Straits (an alternative name for this strait) about 425,000 years ago. A narrow deep channel along the middle of the strait is the remnants of the main (summer) outflow of the northern Ustrom glacial lake (a collect for other then-seasonal rivers, in winter iced up, such as the Thames and Weser) in the last Ice Age. A deposit in

East Anglia East Anglia is an area in the East of England, often defined as including the counties of Norfolk, Suffolk and Cambridgeshire. The name derives from the Anglo-Saxon kingdom of the East Angles, a people whose name originated in Anglia, in ...

marks the old preglacial northward course of the Urstrom-Thames when it also drained

Doggerland Doggerland was an area of land, now submerged beneath the North Sea, that connected Britain to continental Europe. It was flooded by rising sea levels around 6500–6200 BCE. The flooded land is known as the Dogger Littoral. Geological sur ...

. The deep sea floor east of

Lincolnshire Lincolnshire (abbreviated Lincs.) is a county in the East Midlands of England, with a long coastline on the North Sea to the east. It borders Norfolk to the south-east, Cambridgeshire to the south, Rutland to the south-west, Leicestershire ...

and

East Yorkshire The East Riding of Yorkshire, or simply East Riding or East Yorkshire, is a ceremonial county and unitary authority area in the Yorkshire and the Humber region of England. It borders North Yorkshire to the north and west, South Yorkshire to th ...

, connecting to the

Atlantic The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe an ...

via the

Pentland Firth The Pentland Firth ( gd, An Caol Arcach, meaning the Orcadian Strait) is a strait which separates the Orkney Islands from Caithness in the north of Scotland. Despite the name, it is not a firth. Etymology The name is presumed to be a corruption ...

in the last glaciation (of over 300,000 years) is a necessary pre-condition for the relatively late cutting through of the Strait to the south. Strait of Dover MODIS

Likewise, a 2007 study concluded that the Strait was formed by erosion caused by two major floods. The first was about 425,000 years ago, when an ice-dammed lake in the southern North Sea overflowed and broke the Weald-

Artois Artois ( ; ; nl, Artesië; English adjective: ''Artesian'') is a region of northern France. Its territory covers an area of about 4,000 km2 and it has a population of about one million. Its principal cities are Arras (Dutch: ''Atrecht'') ...

(Boulonnais) chalk range in a catastrophic erosion and flood event. Consequently the ice-age-muted flows from the Thames and

Scheldt The Scheldt (french: Escaut ; nl, Schelde ) is a river that flows through northern France, western Belgium, and the southwestern part of Netherlands, the Netherlands, with its mouth at the North Sea. Its name is derived from an adjective corr ...

flowed through the gap into the English Channel/Inlet, but the

Meuse The Meuse ( , , , ; wa, Moûze ) or Maas ( , ; li, Maos or ) is a major European river, rising in France and flowing through Belgium and the Netherlands before draining into the North Sea from the Rhine–Meuse–Scheldt delta. It has a t ...

and Rhine still flowed without any significant link to the inlet (such as today's

IJssel The IJssel (; nds-nl, Iessel(t) ) is a Dutch distributary of the river Rhine that flows northward and ultimately discharges into the IJsselmeer (before the 1932 completion of the Afsluitdijk known as the Zuiderzee), a North Sea natural harbour ...

distributary supports). In a second flood about 225,000 years ago supported by glaciers extending from areas then land such as the

Zuiderzee The Zuiderzee or Zuider Zee (; old spelling ''Zuyderzee'' or ''Zuyder Zee'') was a shallow bay of the North Sea in the northwest of the Netherlands, extending about 100 km (60 miles) inland and at most 50 km (30 miles) wide, with an o ...

, the Meuse and Rhine were ice-dammed into a lake that broke catastrophically through a high weak barrier (perhaps chalk, or an end-moraine left by the ice sheet). Both floods cut massive flood channels in the dry bed of the English Channel, somewhat like the

Channeled Scablands The Channeled Scablands are a relatively barren and soil-free region of interconnected relict and dry flood channels, coulees and cataracts eroded into Palouse loess and the typically flat-lying basalt flows that remain after cataclysmic floods ...

or the

Wabash River The Wabash River ( French: Ouabache) is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map accessed May 13, 2011 river that drains most of the state of Indiana in the United States. It flows fro ...

in the USA. A further update in 2017 attributed a series of previously described underwater holes in the Channel floor, "100m deep" and in places "several kilometres in diameter", to lake water plunging over a rock ridge causing isolated depressions or

plunge pool A plunge pool (or plunge basin or waterfall lake) is a deep depression in a stream bed at the base of a waterfall or Shut-in (river), shut-in. It is created by the erosion, erosional forces of cascading water on the rocks at formation's base wher ...

s. The melting ice and rising sea levels submerged

, the area linking Britain to France, around 6,500–6,200 BCE. The Lobourg strait, the deepest part the strait, runs its wide slash on a NNE–SSW axis. Nearer to the French coast than to the English, it borders the

Varne sandbank The Varne Bank or Varne Shoal is a long sand bank in the Strait of Dover, lying southwest of Dover in Kent, England. With the Lobourg Channel running along it, the Varne bank lies immediately south-west of the deepest point in the strait of ...

(shoals) where it plunges to and further south, the Ridge bank (shoals) (French name "''Colbart''") with a maximum depth of .

Marine wildlife

The depth of the strait varies between at the Lobourg strait and at the highest banks. The seabed forms successions of three habitats: *rocky zones relatively deserted by ships wanting to spare their nets *sandy flats * sub-aqueous dunes. The strong tidal currents of the strait at depth slow around its rocky masses as these stimulate

countercurrents Countercurrent may refer to: *Countercurrent pool *Countercurrent exchange *Countercurrent chromatography *Equatorial Counter Current *''Counter-Currents Gregory Johnson (born 1971) is an American white nationalist and advocate for a white eth ...

and deep, calm pockets where many species can find shelter. In these calmer lee zones, the water is clearer than in the rest of the strait; thus

alga Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular mi ...

e can grow despite the average depth. They help increase diversity in the local species – some of which are

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the strait. Moreover, this is a transition zone for the species of the Atlantic Ocean and those of the southern part of the North Sea. This mix of various environments promotes a wide variety of wildlife. The '' Ridens de Boulogne'', a deep rocky shoal, partially sand-capped, west of

Boulogne Boulogne-sur-Mer (; pcd, Boulonne-su-Mér; nl, Bonen; la, Gesoriacum or ''Bononia''), often called just Boulogne (, ), is a coastal city in Northern France. It is a sub-prefecture of the department of Pas-de-Calais. Boulogne lies on the ...

, boasts the highest profusion of

maerl Maerl (also rhodolith) is a collective name for non-geniculate coralline red algae with a certain growth habit. Maerl grows at a rate of c. 1 mm per year. It accumulates as unattached particles and forms extensive beds in suitable sublitto ...

in the strait. Thus some of the strait is classified as a

Natura 2000 Natura 2000 is a network of nature protection areas in the territory of the European Union. It is made up of Special Areas of Conservation and Special Protection Areas designated under the Habitats Directive and the Birds Directive, respectively ...

protection zone named '' Ridens et dunes hydrauliques du Pas de Calais'' (Ridens and sub-aqueous dunes of the Dover Strait). This includes the sub-aqueous dunes of Varne, Colbart, Vergoyer and Bassurelle, the ''Ridens de Boulogne'', and the Lobourg channel which provides calmer and clearer waters due to its depth reaching .

Unusual crossings

Many crossings other than in conventional vessels have been attempted, including by

pedalo A pedalo (British English) or paddle boat (U.S., Canadian, and Australian English) is a human-powered watercraft propelled by the action of pedals turning a paddle wheel. Description A pedalo is a human-powered watercraft propelled by the ...

jetpack A jet pack, rocket belt, or rocket pack is a device worn on the back which uses jets of gas or liquid to propel the wearer through the air. The concept has been present in science fiction for almost a century and became widespread in the 1960s. ...

bathtub A bathtub, also known simply as a bath or tub, is a container for holding water in which a person or animal may bathe. Most modern bathtubs are made of thermoformed acrylic, porcelain-enameled steel or cast iron, or fiberglass-reinforced poly ...

amphibious vehicle An amphibious vehicle (or simply amphibian), is a vehicle that is a means of transport viable on land as well as on or under water. Amphibious vehicles include amphibious bicycles, ATVs, cars, buses, trucks, railway vehicles, combat vehicles an ...

and more commonly by

swimming Swimming is the self-propulsion of a person through water, or other liquid, usually for recreation, sport, exercise, or survival. Locomotion is achieved through coordinated movement of the limbs and the body to achieve hydrodynamic thrust that r ...

. Since

French law The Law of France refers to the legal system in the French Republic, which is a civil law legal system primarily based on legal codes and statutes, with case law also playing an important role. The most influential of the French legal codes is ...

bans many of them, unlike

English law English law is the common law legal system of England and Wales, comprising mainly criminal law and civil law, each branch having its own courts and procedures. Principal elements of English law Although the common law has, historically, be ...

, most such crossings originate in England.

Ice

In the late 17th century during the "

Little Ice Age The Little Ice Age (LIA) was a period of regional cooling, particularly pronounced in the North Atlantic region. It was not a true ice age of global extent. The term was introduced into scientific literature by François E. Matthes in 1939. Ma ...

", there were reports of severe winter ice in the English Channel and Strait of Dover, including a case in 1684 of only a

league League or The League may refer to: Arts and entertainment * ''Leagues'' (band), an American rock band * ''The League'', an American sitcom broadcast on FX and FXX about fantasy football Sports * Sports league * Rugby league, full contact footba ...

of open water remaining between Dover and Calais.

Notes

External links

Channel Navigation Information Service

Channel Swimming & Piloting Federation

Channel Swimming Association

Depth Chart showing straits and former course of Rhine
{{Authority control Straits of England Landforms of Kent Port of Dover, Kent English Channel France–United Kingdom border International straits Straits of Metropolitan France Landforms of Hauts-de-France