In 1824 Sopwith completed an apprenticeship with his father, and took employment as a surveyor. He worked closely with Richard Grainger in the redevelopment of Newcastle Upon Tyne. He worked with Joseph Dickinson of Alston, Cumbria, on a survey of the lead mines in the area owned by Greenwich Hospital. He later built up contacts in London, especially in the area of geology, where he became a fellow of the Geological Society (and its more exclusive Geological Club) in 1835, sponsored by John Phillips.