Artists have been depicting the Thames for over 500 years.  Normally they painted scenes up river from London Bridge. Yet the Lower Thames had its artistic admirers: some of them, like Turner and Constable, are well known.  Yet there is a welter of distinguished watercolour artists who depicted the Medway and the Lower Thames, about whom we hear far less, such as Paul Sandby who portrayed Rochester’s medieval bridge and castle, and John Cotman and William Wyllie.  Then there was the Dutch Raid on the Medway in 1667, portrayed it in great accuracy in at least four paintings.  For an unusual slant on the Thames, this tour of the Lower Thames and its tributaries will surprise those who thought they knew the river well.