In this powerful painting, the line of prison ships forms a dark diagonal across the image from the left foreground to the centre of the picture. Behind these ships, to the south-east, lies the town of Portsmouth, its skyline visible against the sky in the centre, with Gosport to the right and the entrance to the Harbour in the centre. To the right other ships, with pennants flying, are also anchored 'in ordinary' (reserve) in the Upper Harbour. Among them is a fully rigged two-decker flying Spanish colours, which suggests the picture dates from after May 1808, when Spain became a British ally against Napoleon and such a ship would have been a friendly visitor rather than a prize of war. In the foreground small craft have been depicted with their sails billowing in the stiff breeze. Two appear to be using forms of Mediterranean lateen sail: the large boat at centre is a 'settee' sailn with which ships' launches and longboats were equipped but which are rarely seen in paintings of British subjects. Ashore, in the far left background there appears to be a large store area of ochre-coloured brushwood or similar fuel for 'breaming' ships' hulls during refit (burning off marine growth): as a considerable fire risk it is outside the town and dockyard area. A swathe of pink cloud dominates the picture and symbolically progresses from dark immediately above the hulks to a more brilliant light above the channel leading to the open sea and France.

The loss of the American colonies in the 1770s as a place to send convicts condemned to transportation, created an acute shortage of prison space. There was not time to build more prisons so as a temporary measure some ships were converted into prison hulks, which could easily be made secure although the conditions aboard their often-rotting hulls were tough. It was during the French Wars of 1793 to 1815 that the greatest use of hulks was made to accommodate additional prisoners of war. They included the artist, Louis Garneray, who was captured from a French privateer and was one of a family of artists. Garneray later wrote three popular autobiographies recounting his adventurous double career as a sailor, sometime corsair, and an artist.

After leaving home aged 13 to go to sea, he quickly discovered that captains wanted him to depict their brave deeds, which he did until he was captured by the English in 1806. From then until 1814 he was detained in the harbour at Portsmouth, imprisoned on various 'pontons' (prisons made from the hulks of captured and disabled French or other ships moored in the mud) but somehow managed to paint and sell his work for a pittance. This helped improve his conditions in captivity, in the way that many other prisoners also did by making ship models or other handicrafts. He produced a larger version of this painting on canvas in 1814. (See also the two other versions in the Museum collection, BHC1924 and BHC1925.) When Napoleon abdicated in 1814, the British freed their prisoners and Garneray returned to Paris, continuing to work as an artist. From 1817, by working for the Duc d'Angouleme, then Grand Admiral of France, he became in effect France's first 'Peintre officiel de la Marine' although this (continuing) corps was not formally established until 1830. From 1833 he was director of the museum at Rouen, but continued to paint for the rest of his life.