One of the group of large oil sketches of Thames subjects from the Turner Bequest (see Nos.143-6). However, even though some of the sketches may have been painted on the spot, it is difficult to imagine Turner managing a canvas of this size in the middle of the Thames Estuary. As in most of the finished oils discussed under No.153 the distant town appears to be Sheerness, but none of the details of this sketch are repeated in the finished works. It is presumably therefore an essay on the same theme done before Turner turned to painting it for exhibition, which supports the traditional dating of c. 1807 or 1808 at the latest.