Thames Estuary

The upper part of the estuary from Tilbury to Mucking Creek looking north from Shorne, which is 4 kilometres (2.5 mi) south of the river

The appellation Greater Thames Estuary[5] applies to the coast and the low-lying lands bordering the estuary itself. These are characterised by the presence of mudflats, low-lying open beaches and salt marshes, namely the North Kent Marshes and the Essex Marshes. Man-made embankments are backed by reclaimed wetland grazing areas, but rising sea levels may make it necessary to temporarily flood some of that land in places at spring tides, to take the pressure off the defences.

The Blackwater Estuary, on the Essex coast, in the northern part of the Greater Thames Estuary. Mersea Island is on the right.

There are many smaller estuaries in Essex, including the Rivers Colne, Blackwater and Crouch. Small coastal villages depend on an economy of fishing, boat-building, and yachting.[6] The Isle of Sheppey, the Isle of Grain, Canvey Island, Two Tree Island, Havengore Island, New England Island, Rushley Island, Potton Island, Foulness Island and Mersea Island are part of the coastline.[7]

Where higher land reaches the coast there are some larger settlements, such as Clacton-on-Sea to the north in Essex, Herne Bay, Kent, and the Southend-on-Sea area within the narrower part of the estuary.

The River Thames flowing through London is a classic river estuary, with sedimentary deposition restricted through manmade embankments. The district of Teddington a few miles south-west of London's centre marks the boundary between the tidal and non-tidal parts of the Thames, although it is still considered a freshwater river about as far east as Battersea insofar as the average salinity is very low and the fish fauna consists predominantly of freshwater species such as roach, dace, carp, perch, and pike. The Thames Estuary becomes brackish between Battersea and Gravesend, and the diversity of freshwater fish species present is smaller, primarily roach and dace, euryhaline marine species such as flounder, European seabass, mullet, and smelt become much more common. Further east, the salinity increases and the freshwater fish species are completely replaced by euryhaline marine ones, until the river reaches Gravesend, at which point conditions become fully marine and the fish fauna resembles that of the adjacent North Sea and includes both euryhaline and stenohaline marine species. A similar pattern of replacement can be observed with the aquatic plants and invertebrates living in the river.[9][10]

Joseph Conrad lived in Stanford-le-Hope close to the Essex marshes. His The Mirror of the Sea (1906) contains a memorable description of the area as seen from the Thames. It is also described in the first pages of Conrad's Heart of Darkness, as both the launching place of England's great ships of exploration and colonization and, in ancient times, the site of colonization of the British Isles by the Roman Empire.

Accent

The form of speech of many of the people of the area, principally the accents of those from Kent and Essex, is often known as Estuary English. The term is a term for a milder variety of the "London Accent". The spread of Estuary English extends many hundreds of miles outside London and all of the neighbouring home counties around London have residents who moved from London and brought their version of London accents with them leading to interference with the established local accents. The term London Accent is generally avoided as it can have many meanings. Forms of "Estuary English" as a hybrid between Received pronunciation and various London accents can be heard in all of the New Towns, all of the coastal resorts and in the larger cities and towns along the Thames Estuary.

For commercial shipping approaching the Nore and thus London, main deep-water routes were the Princes Channel, the Queens Channel and the South Channel to the south, to a lesser extent the Kings Channel and the Swin to the north. The Swin was used by barges and leisure craft from the Essex rivers, and coasters and colliers from the north east. These channels were made up of natural troughs; Yantlet Channel (Sea Reach), Oaze Deep, Knock John Channel, Black Deep Channel which have been extensively marked. These are separated by slow moving sandbanks with names such as the East and West Barrows, the Nob, the Knock, the John, the Sunk, the Girdler, and the Long sands. [11]

The shallow bottomed barges and coasters would navigate the swatchways at flood tide, and would cross the sand banks at spitways, points where the water was least shallow, and just deep enough at that point of the tide. If they missed the moment they would heave to and wait for the next tide.

Recreational craft are expected use channels most suited to the size of their vessel. When navigating to or from the north they should use the Middle Deep, Swin and Warp. Barrow Deep and Warp. When navigating to or from the south, they should use the Horse and Gore and Four Fathom Channels.

To cross the estuary large vessels used Fisherman's Gat, and small vessels to were expected to use Foulger's Gat.[12]

This table shows, from west to east, the principal navigation lights, buoys and other marks to the north (port) and south (starboard) of the main deep-water channels of the River Thames from Gallions Reach to the Sunk Light Float.[13][14][15][16][17] The Thames is in IALA region A so port buoys are red and starboard buoys are green.

Thames estuary navigation marks

Notes

• Locations of deeps and shallows and buoys in the Thames estuary