Ship portrait. A portrait of the Britannia, broadside to port, entering Portsmouth Harbour. The buildings of Portsmouth Dockyard can be seen in the distance to the left and on the far right on either side of the harbour wall. In the foreground are several small boats with men variously occupied attending to them. A ship at anchor can be seen in the distance on the left. A yacht with a crowded deck is visible on the right. There is a barrel in the water on the left.

Built in 1820, the 'Britannia' returned from the Mediterranean in 1835. From 1836, she was flagship at Portsmouth and remained there until she went out of commission from 1842. The artist learned to paint while he was serving in the Royal Navy. He later took up painting as a profession to augment his half pay and concentrated on Royal Naval subjects.

R.S. Thomas was a lieutenant but was forced by deafness to give up active service in 1814. He is known to have been living in Portsmouth in the early 1840s.