Abbey River Tideway where there are two larger islands. It is much smaller than Canvey Island and the Isle of Sheppey and narrowly ahead of Andersey Island facing Abingdon-on-Thames, another market town with an abbey which had multiple medieval mills, another of note being Westminster Abbey, the island of which Thorney Island no longer exists. The outfall of the Abbey River is 400 m above Chertsey Bridge, into the weir pool of Chertsey Weir. The manmade strictly-considered "island" the bypass channel forms is outranked in size since the 2002 completion of the Jubilee River by the example containing Dorney and Eton, Berkshire.
Canvey Island been discharged into the river by the means of seven sluices (later known as Commissioners Dykes). The completion of the work saw a considerable number of the Dutch engineers take land as payment for their work, and consequently settle on the island. Approximately one-third of Canvey's streets have names of Dutch origin. The coast of Canvey Island was host to the Chapman Lighthouse as briefly described in Joseph Conrad's novel "Heart of Darkness". It is believed that the peril of the mudflats below such shallow waters off the Canvey Island coast prompted the Romans to devise some form of beacon