Jan van Os, 'Dutch Vessels in Calm Water', probably 1770-85

In one small picture, Jan van Os manages to combine feelings of tranquillity and industry. The sea is calm but dotted with craft in every state of readiness to sail. Overhead, puffy clouds seem to hang motionless over the scene. Below, the sails of the small boat coming towards us are filled with wind, its little red topsail jaunty, its broad white sails elegant. Yet there’s no wake bubbling along its sides, as there should be if it were moving.

Van Os fills the picture with sky. He restricts the action to the bottom quarter of the oak panel, giving a sense of almost endless space. But in every vessel in eyeshot there are people, often in silhouette, to give the picture energy and character. By placing a vessel close to us on either side, he narrows the view a little and directs our attention towards the open sea. But the main pointer to the distance, and the unknown, is the urgent gesture of a man in a padded brown coat and a red hat. He sits in the boat drawn up on the beach on the left. He’s hunched forward, his arm outflung, his finger pointing. We, along with the man with a basket tied round his waist, peer forward to see what’s out there.

The man’s little boat is a kaag, a small shallow-bottomed vessel that stayed fairly close to shore, often used as one of the many ferries between towns (the normal form of transport in the Netherlands at the time). Van Os has shown every detail of the broad overlapping planks of the keel, the fine, spidery lines of the rigging and the folds of the brown sail – perhaps not stowed as tidily as some might be. Another man shakes his mop over the side after sluicing the deck.

The tjalk with red sails (a Dutch passenger ship) on the right flies two flags, one on either mast. The tiny monogram on the white central band of the Dutch flag – ‘VOC’ – shows that this vessel belongs to the Dutch East India Company, the powerful trading organisation largely responsible for the upsurge in commerce in the Netherlands in the seventeenth century. Their giant merchant vessels sailed to the East Indies, Africa and China bringing home wealth and luxuries. Van Os, like the greater part of the population, must have been aware of the importance of the company to the prosperity of the country. He perhaps included the flags on one of their smaller, inshore vessels as a reminder of its role in their lives.

Van Os was far better known for flower paintings in the style of Jan van Huysum than for marine subjects. In this picture, he harks back to the style of Willem van de Velde or Jan van de Cappelle, both painting more than a century earlier.