This drawing covers Canvey Island. Red triangulation lines are marked, radiating from the centre of settlements and from trigonometrical stations, denoted by the word 'Flag', as at Canvey Point. The draughtsman has shown the channels and sandbanks of the Bemfleet Creek, noting that one bank is only dry at spring tides.A dominant feature of the coastline is the sea wall, represented by a thick grey angular line extending all the way up the creek. Built to protect vulnerable marshland from the sea, the wall benefited from Dutch reclamation work in the 17th century but did not withstand serious floods in 1791, after which further repair work was essential. An Act of Parliament in 1792 established a board of commissioners to build new sections of wall behind the existing one in the places where breaches had occurred. This can be seen on Fobbing Marsh and around Shell Haven Creek in this 1798 drawing. Area calculations appear in the bottom left.