Jan van Goyen, 'An Estuary with Fishing Boats and Two Frigates', about 1650-6

Huge clouds float across a wide sky, seeming to dwarf everything below – even the two frigates heading way out to sea, sails raised, tall and majestic. From the gunports of one, a cannon blazes in salute to signal their departure. The puffs of smoke are painted with light, airy swirls of white, making miniature versions of the clouds overhead; there’s even a tiny, but brilliant, flash of gold and orange from the unseen cannon’s mouth.

Although these two stately ships are in the distance, they are the focus of the picture. Van Goyen placed the closer figures in their fishing boats in deep shadow, almost in silhouette, making them seem incidental. Frigates were light warships that protected the giant merchant vessels that were the lifeblood of the new Dutch Republic, reaching out across the world and bringing wealth to the small but powerful nation. And van Goyen has positioned them almost centrally, with a clear sweep of water between them and us – it’s as if everything has moved aside to allow them freedom of the waterways.

The sea is calm, the reflections on its surface clear and barely rippled – even the gun smoke is mirrored as if there’s another cannon firing under the water. The men in the small boats go about their tasks or sit, simply taking in the view. But they don't look at the departing frigates: to them, the ships have become a part of everyday life. Beyond the slackened, tawny brown sail of the fishing boat, the sails of a windmill stretch up to catch a sudden glimpse of the sun – two kinds of sail that appear like a repeating rhythm through Dutch land and seascapes of the time.

Van Goyen has given us a panoramic view, but also many minute details. Two fishing nets stand up like transparent flags in the larger boat out by the little island. Big round baskets await a catch in the rowing boat close to us. Beside it, a bare branch seems to curve round to point the way for the two frigates.

We don’t know if the painting represents a specific place. It’s probably an amalgamation of small scenes from van Goyen’s many drawings. These were made on the spot and out of doors, but the final painting was worked up in the studio (standard practice at the time). He worked extremely fast, sometimes painting a picture in a day, but this speed didn’t stop him from portraying poetic visions of the Dutch landscape that hold the gaze and appeal to the imagination. This picture is quiet and serene and, with the towering sails on the departing ships, the tiny Dutch flag fluttering from the fishing boat and the upward sweep of the sunlit clouds, somehow buoyant and full of hope.