There is a black chalk study for the present watercolour in the R.J. Colman bequest at Norwich Castle Musuem, but without the boat on the left hand side. The watercolour was described as Fishing Boats, Carrow in the 1886 Norwich Art Circle exhibition (see M. Allthorpe-Guyton, John Thirtle 1777-1839, Drawings in Norwich Castle Museum, exhibition catalogue, 1977, p 63)