HMS 'Exmouth' was a screw second-rate ship of 90 guns laid down at Devonport in 1840, but not commissioned by the Royal Navy until the mid-1850s. In 1876 she was loaned to the Metropolitan Asylum Board as a training ship on the Thames to replace HMS 'Goliath', which had been destroyed by fire the previous year. She had accommodation for 750, mainly boys from poor circumstances, and her staff, usually former members of the Royal Navy, ran the ship along naval lines.

This watercolour shows the ship at night and possibly dates from the mid-1880s when Wyllie made an etching of her. It reveals an awareness of James Abbott McNeill Whistler's 'Nocturnes' painted in the 1870s, which Wyllie would have seen.