A third-rate, two-decker, 74-gun warship is shown flying the red ensign and private pennant on the left of the picture, in the outer part of Port Mahon harbour, Minorca. A ship of this size could have been used for lying in line of battle, as an independent cruiser or the flagship of a small squadron. This one is in fact hove-to and making little way, to drop a boat which is conveying two naval officers to the quayside on the right. The boat, also flying the red ensign, has a smartly uniformed crew which suggests it is taking the captain ashore at Es Castell, the small town which lies between Port Mahon and the mouth of the harbour, on its south side. The red building is one of two which still survive there. Other ships lie behind off the harbour entrance. In the foreground is a variety of small craft including a rowing boat on the left, with a man holding a net spread over the water. In the central foreground a felucca, a type of narrow, swift, lateen-rigged sailing vessel used in the Mediterranean, moves towards a small landing stage. At back left lies the early 19th-century lazaretto or quarantine hospital on what was then the Felipet peninsula, which in 1900 was made into an island by a short canal across its narrow landward end. This was completed in its original form in 1817 as what became Spain's main 19th-century quarantine station, Minorca having finally been returned to Spain in 1802 after its final British occupation from 1798. The artist has incorporated detailed elements of everyday life, such as washing hanging on a line, a woman carrying a basket on her head, a man with his fishing rod and inhabitants wearing their traditional dress. This is an unusual, large composition by an artist more widely known for small-scale paintings in the Dutch manner and stylistically it hovers between the 18th and 19th centuries.

Powell (1775-1824) came from Chichester and spent some time at sea, presumably early in life since he was regularly exhibiting in London from 1807. This is not one of his exhibited works and was probably therefore a commission, perhaps for the captain of the unidentified vessel shown. It is signed and dated 'C M Powell 1820' in the bottom right-hand corner.