Quiet Street Antiques of Bath has dated this piece to the 1800s.
On the Thomas Agnew label on the reverse it is inscribed with details of its exhibition (1959) and a cutting from an old auction catalogue.

Although inscribed as by William Joy (1803-1867), it is known that most of his work was a joint production with John Cantiloe (1806-1866). In 1832 they moved to Portsmouth where they were employed by the Government to paint various types of fishing boats. See "Dictionary of British Painters" by Christopher Wood page 261
Quiet Street Antiques of Bath has dated this piece to the 1800s.
Fine antiques at sensible prices
You can view the stock and full dealer information on the Quiet Street Antiques of Bath Profile Page