Lower Horse of islands (five of which later re-clustered to form Canvey Island), that broke away from the English coastline in the medieval period. Lower Horse Lower Horse is a uninhabited island off the English coast, lying in the Thames Estuary between Canvey Island and Stanford-le-Hope, close to . Administratively it is part of Thurrock unitary authority; the border with its ceremonial county namely the administrative county of Essex runs between it and Canvey Island. Smaller than normal markings for an area of saltings (traditional, open air, sea salt extraction through drying) appear in the Ordnance Survey map of 1919, which confirms
Estuary river valleys are also known as coastal plain estuaries. In places where the sea level is rising relative to the land, sea water progressively penetrates into river valleys and the topography of the estuary remains similar to that of a river valley. This is the most common type of estuary in temperate climates. Well-studied estuaries include the Severn Estuary in the United Kingdom and the Ems Dollard along the Dutch-German border. The width-to-depth ratio of these estuaries is typically large, appearing wedge-shaped (in cross-section) in the inner part and broadening and deepening seaward. Water depths rarely exceed . Examples of