The Black Deep is a channel which forms the most important of the three main permanent shipping routes through the shoal

Shoal

Shoal, shoals or shoaling may mean:* Shoal, a sandbank or reef creating shallow water, especially where it forms a hazard to shipping* Shoal draught , of a boat with shallow draught which can pass over some shoals: see Draft...

s in the Thames Estuary

Thames Estuary

The Thames Mouth is the estuary in which the River Thames meets the waters of the North Sea.It is not easy to define the limits of the estuary, although physically the head of Sea Reach, near Canvey Island on the Essex shore is probably the western boundary...

, the others being the Barrow Deep and Princes Channel.

The Black Deep begins in the open sea and is bounded by two substantial sandbanks, the Sunk Sands to the north and west and the Long Sands to the south and east. Deep-draught

Draft (hull)

The draft of a ship's hull is the vertical distance between the waterline and the bottom of the hull , with the thickness of the hull included; in the case of not being included the draft outline would be obtained...

 vessels making for the Port of London

Port of London

The Port of London lies along the banks of the River Thames from London, England to the North Sea. Once the largest port in the world, it is currently the United Kingdom's second largest port, after Grimsby & Immingham...

 from the North Sea

North Sea

In the southwest, beyond the Straits of Dover, the North Sea becomes the English Channel connecting to the Atlantic Ocean. In the east, it connects to the Baltic Sea via the Skagerrak and Kattegat, narrow straits that separate Denmark from Norway and Sweden respectively...

 approach from the north-east from the position of the Sunk lightship, pass through the Black Deep, and thence into the Knock John channel to enter the Thames. Large Bulk carrier

Bulk carrier

A bulk carrier, bulk freighter, or bulker is a merchant ship specially designed to transport unpackaged bulk cargo, such as grains, coal, ore, and cement in its cargo holds. Since the first specialized bulk carrier was built in 1852, economic forces have fueled the development of these ships,...

s also cross the area when entering or exiting the River Medway

River Medway

The River Medway, which is almost entirely in Kent, England, flows for from just inside the West Sussex border to the point where it enters the Thames Estuary....

, as it has a minimum depth of at least 14 metres.

History

The Thames Estuary was historically a difficult area to navigate due to its many sandbanks. One of the earliest references to maritime pilot

Maritime pilot

A pilot is a mariner who guides ships through dangerous or congested waters, such as harbours or river mouths. With the exception of the Panama Canal, the pilot is only an advisor, as the captain remains in legal, overriding command of the vessel....

age dates from 1387 and refers to a pilot "of the Black Deeps" in the estuary. Richard Caundish, the sixteenth-century maker of the oldest known English maritime chart, who had charted the Thames shoals, was assisted by a pilot who had found a new, safer route through the Black Deep.

As a strategically important area, access to the Deep has been restricted in wartime, while during the Second World War naval forts

Maunsell Forts

The Maunsell Forts were small fortified towers built in the Thames and Mersey estuaries during the Second World War to help defend the United Kingdom. They were named after their designer, Guy Maunsell. The forts were decommissioned in the late 1950s and later used for other activities...

 were constructed at Sunk Head and Knock John to deter German minelaying activity. Until 1967 sewage

Sewage

Sewage is water-carried waste, in solution or suspension, that is intended to be removed from a community. Also known as wastewater, it is more than 99% water and is characterized by volume or rate of flow, physical condition, chemical constituents and the bacteriological organisms that it contains...

 sludge from the City of London was dumped in the Black Deep at a point around sixty miles below London Bridge

London Bridge

London Bridge is a bridge over the River Thames, connecting the City of London and Southwark, in central London. Situated between Cannon Street Railway Bridge and Tower Bridge, it forms the western end of the Pool of London...

; after this time the Barrow Deep was used.

A rumour current in the sixteenth century, repeated by the chroniclers John Rastell

John Rastell

John Rastell was an English printer and author.-Life:Born in London, he is vaguely reported by Anthony à Wood to have been "educated for a time in grammaticals and philosophicals" at Oxford. He became a member of Lincoln's Inn, and practised successfully as a barrister. He was also M.P...

 and Edward Hall

Edward Hall

Edward Hall , English chronicler and lawyer, was born about the end of the 15th century, being a son of John Hall of Northall, Shropshire....

, by a continuer of John Hardyng

John Hardyng

John Hardyng , English chronicler, was born in the north.As a boy he entered the service of Sir Henry Percy , with whom he was present at the Battle of Shrewsbury . He then passed into the service of Sir Robert Umfraville, under whom he was constable of Warkworth Castle, Northumberland, and Kyme...

's chronicle and subsequently by John Speed

John Speed

John Speed was an English historian and cartographer.-Life:He was born at Farndon, Cheshire, and went into his father's tailoring business where he worked until he was about 50...

, suggested that Richard III

Richard III of England

Richard III was King of England for two years, from 1483 until his death in 1485 during the Battle of Bosworth Field. He was the last king of the House of York and the last of the Plantagenet dynasty...

, aided by the priest of Sir Robert Brackenbury

Robert Brackenbury

Sir Robert Brackenbury was an English nobleman and courtier. He was a close associate of Richard III of England.-Early life:...

, had disposed of the bodies of the murdered Edward V of England

Edward V of England

Edward V was King of England from 9 April 1483 until his deposition two months later. His reign was dominated by the influence of his uncle Richard, Duke of Gloucester, who succeeded him as Richard III...

 and Richard of Shrewsbury, 1st Duke of York

Richard of Shrewsbury, 1st Duke of York

Richard of Shrewsbury, 1st Duke of York, 1st Duke of Norfolk, 1st Earl of Norfolk, Earl Marshal was the sixth child and second son of King Edward IV of England and Elizabeth Woodville. He was born in Shrewsbury....

 in the Black Deep, "whereby they should never rise up, or be any more seen".

Through much of the 1980s, Knock John Deep was the anchorage spot for Radio Caroline

Radio Caroline

Radio Caroline is an English radio station founded in 1964 by Ronan O'Rahilly to circumvent the record companies' control of popular music broadcasting in the United Kingdom and the BBC's radio broadcasting monopoly...

s Ross Revenge

Ross Revenge

The MV Ross Revenge is a radio ship, formerly the home of Radio Caroline, as well as having supported Radio Monique and various religious broadcasters. She was constructed in Bremerhaven in 1960, and initially served as a commercial trawler, notably taking part in the cod wars of the 1970s...

 ship

The proposed London Array

London Array

The London Array is an offshore wind farm under construction in the outer Thames Estuary in the United Kingdom. With 1,000 megawatt capacity, it is expected to become the world's largest offshore wind farm. The site is off the North Foreland on the Kent coast in the area of Long Sand and...

 wind farm

Wind farm

A wind farm is a group of wind turbines in the same location used to produce electric power. A large wind farm may consist of several hundred individual wind turbines, and cover an extended area of hundreds of square miles, but the land between the turbines may be used for agricultural or other...

will be sited immediately to the east of the Deep.