By the mid-seventeenth century the Dutch were the greatest sea power in the world. Their ships dominated the oceans, ensuring not only the military security of the Republic but also its prosperity. Indeed, the combination of regional and global trade brought everything from exotic spices to bulk staples, such as grain and salt, to the Dutch ports.

Simon de Vlieger's most innovative paintings, including this Estuary at Day’s End, capture the flavor of daily life along the Dutch coast. In this restrained and sensitive composition, two workers apply tar to the hull of a ship resting on a sandbar at low tide. Black smoke from the fire that heats the tar rises up toward the towering clouds, while dramatic rays of light break through the thinner layer of clouds on the left. In the background, smoke erupts from the cannon of a large Dutch ship firing a salute. The scene is simple, but the effects of light and atmosphere give the painting a tremendous sense of drama, and these qualities can be fully appreciated thanks to the work's remarkable state of preservation.

De Vlieger was one of the most important and influential Dutch marine painters. A versatile artist, he was equally comfortable painting dramatic storms or stately naval parades, all of which he enlivened with small figures carefully situated within the pictorial context. He clearly knew the sea and the ships that sailed it: he accurately recorded the distinguishing features of the various types of vessels—from large navy ships to small fishing and transport boats—and set them convincingly in the water. But De Vlieger's sensitivity to the atmospheric effects of water and sky along the North Sea truly separates him from most other marine painters. He was unmatched in capturing the subtle ranges of grays and gray-blues found along coastal waters.