Love, loss, and memory drove Hartley to create his most compelling images. Hartley painted several works depicting boats on a rough ocean in an emotional response to the drowning of close friends—the brothers Alty and Donny Mason—off the Nova Scotia coast in 1936. He had formed an intimate relationship with the entire Mason family while boarding with them in Nova Scotia (1935—1936) and was distraught over the fateful accident. In Off the Banks at Night, two boats are adrift while ominous clouds hover overhead and waves crash against jagged rocks in the foreground. A larger version of an earlier painting done at the time of the incident, this composition is simpler and more abstract than the earlier work. The clouds are consolidated into angular shapes, and the rocks resemble threatening, sharp teeth.
Throughout his career Hartley acknowledged the strong influence of Albert Pinkham Ryder, and Duncan Phillips recognized this affinity when he described his work as "Ryderesque, but in the quickened tempo of our time." In Off the Banks at Night, Hartley, like Ryder, reduced forms to their expressive essences and heightened color contrasts, striving for the most abstract, dramatic scene possible.