The original title of this painting is not known although a label on the reverse identifies it as showing William John Foster on board his yacht 'Alarm'. In fact there is no documentary evidence that Forster ever owned the yacht since it was built at Lymington in 1830 for the famous yachtsman and landowner Joseph Weld (1777-1863) of Lymington and Lulworth Castle, Dorset. It was of 193 tons, was a cutter-rigged yacht until rebuilt as a schooner in 1852, and one of the most famous 19th-century British yachts. Although the circumstances surrounding the painting are unclear, it is an important deck-view representation of a sailing yacht from the mid-19th century, looking forward.

The background, visible on the port bow, is possibly the Mewstone at Plymouth, so the 'Alarm' could be departing for a day's racing in Plymouth Sound. Three crew are busy forward about the jib, preparing to cast off a mooring, and one crewman prepares to hoist a flag. The steward on the right walks towards the saloon companionway carrying a ham, his sweater embroidered with the name 'Alarm'. The central figure in a top hat, seated, is probably Joseph Weld. The balding man in a pea jacket carrying his cap is a professional skipper, and seems to be taking instructions from the young man with the outstretched arm. Wearing braided navy-style cap, yachting jacket, white waistcoat and duck trousers and holding a cigar, this is probably William John Forster or perhaps Joseph Weld Junior, (1815-89). On the far left, the man with outstretched legs wearing a yachting jacket, dark trousers and black hat, could equally be William John Forster. As a member of the Royal Western Yacht Club he was entitled to fly the Blue Ensign, visible in the bottom left corner. Joseph Weld was an honorary member and full member of the Royal Yacht Squadron, whose name appears on the highly ornate frame together with the club's emblem of a crown and anchor. The artist has observed a variety of detail on the yacht such as the signal guns and the saloon stove chimney in the foreground. The picture however remains something of a puzzle, both from the uncertain identification of those shown except Weld senior, and the fact that while Foster's name is known as a yachtsman, there is no evidence of him owning 'Alarm'. Trained by his father, the artist became an appreciated painter in England. He exhibited from 1842-45 in the Royal Academy in London and lived and worked in Plymouth, England.