When Ostend was first exhibited in 1844, viewers were left guessing about its subject, as Joseph Mallord William Turner gave little away in his titles or catalog entries. The painting’s swirling masses of color and light, barely anchored by recognizable forms, fueled debate among critics who struggled to reconcile its radical style with traditional expectations of marine painting. Some contemporary reviewers, bewildered by Turner's late works, accused him of "wilful obscurity," while others sensed a deliberate attempt to capture something beyond the literal.

The mystery of the scene—whether it is a storm, a harbor, or an allegory—remains a point of fascination. The canvas immerses the viewer in the tumult of the North Sea off the Belgian coast, with the port city of Ostend glimpsed through a haze of spray and cloud. Turner chooses the moment when a steamer, its smokestack billowing, battles rough waves, dwarfed by the vastness of sea and sky. The paint itself seems to churn, with thick, agitated brushstrokes suggesting both the movement of water and the instability of weather.

A faint suggestion of sails and rigging hints at the presence of other vessels, but details dissolve into light and atmosphere. Unlike Claude-Joseph Vernet's calm and orderly harbors, Turner's Ostend offers only fleeting clarity, as if the viewer is caught in the storm alongside the ships. The exact medium of Ostend is uncertain—some sources describe it as oil, others as watercolor heightened with bodycolor—reflecting Turner's experimental approach in his later years. The painting is not known to have been commissioned, and its early provenance is unclear, though it was likely exhibited at the Royal Academy in London.

Today, Ostend is held in a public collection, a testament to the enduring fascination with Turner's late seascapes. Created during a period when Turner was pushing the boundaries of representation, it stands among the works that inspired both confusion and admiration in his own time, and which would later influence the rise of Impressionism.