Thames Estuary Airport a major International hub at Cliffe which would link in with the HS1 line through Kent to St Pancras. The Cameron government was committed to a full Aviation Review and a scoping study was released in March 2011. The "Marinair" proposal was put forward in the 1990s, in which an airport would be built on an offshore artificial island in the Thames estuary, north east of the Isle of Sheppey. When the proposal was put forward again in the government's 2002 consultation, it was rejected on the grounds of insufficient information and prohibitive expense. The Marinair plans had been developed
Severn Estuary the line between Lavernock Point and Sand Point is the Bristol Channel, which in turn discharges into the Celtic Sea and the wider Atlantic Ocean. The islands of Steep Holm and Flat Holm are located close to that line, in the middle of the estuary. Sometimes the term "Severn Estuary" is used to include the tidal upstream stretch between Gloucester and Aust. During the highest tides on the upper reaches of this stretch, the rising water is funnelled up the estuary into the Severn bore, a self-reinforcing solitary wave that travels rapidly upstream against the river current. The tidal range