Rough Sea

Water was both danger and fortune for the Dutch Republic, and this canvas holds both. The museum places the scene on the IJ, the broad estuary that served as Amsterdam's harbour, where Ruisdael had lived since the late 1650s. Whitecaps run across the water and the boats heel hard over in the wind. At the lower left a few broken piles stick out of the waves, a warning of shallow water, yet the ship in front is holding a safe course. Sunlight breaking through the retreating storm catches its sail and the Dutch flag, and the museum suggests Ruisdael may have meant that fortune favoured the Dutch.

He painted it around 1670, on a canvas well over a metre wide, and seascapes are rare in his work. In 1929 its owner, Sir Otto Beit, lent it to the great exhibition of Dutch art at the Royal Academy in London.