A line of merchant ships with a coastline in the distance. They were engaged in transatlantic trade and on these grounds it has been suggested that they are shown off the coast of New England, though this is only speculation: it may be of their as yet unidentified home port in England. The ship in the foreground to the right bears the name 'Castor' on the stern. Four ships of that name were built and it is likely that this painting depicts that built in 1782 by Spedding and Company, Whitehaven.

The ship was built with 18-guns, and it traded to Philadelphia, the West Indies and New York. She saw service for seven years, commanded by Daniel Brocklebank, after which time she was sold. Figures can be seen on the deck of the 'Castor', preparing the ship to sail. The ship at anchor on the left has the name 'Mars', a ship built by the Scottish firm, Wise and Co. The ship on the far right bears the name 'Iris' on her stern and that between her and the 'Castor', with only the after part visible, bears the name 'Mariner' on hers. All the ships are flying the 1801 red ensign. A small boat in the foreground rows across the line of ships, with five figures on board.

Luny was a skilled ship portraitist and from the late 1780s onwards he painted a great number of works depicting ships of the East India Company, and others. This painting, which was produced before he started keeping a list of his output in 1807, was probably commissioned either by one of the ship's captains, who wanted to have a record of the ships they had sailed on, or a merchant involved in the trade shown. The artist has inscribed the painting 'T Luny 1802', on a spar on the left.