By 1915 Potthast began to portray the ocean beaches adjacent to New York City, a subject with which he is closely identified. His paintings, which are undated, bear titles of Coney Island, Manhattan, Brighton, Rockaway, and even Long Beach which indicates the extent of Potthast's excursions along the Long Island shore. While recent writers have linked Potthast's beach scenes with the painters surrounding Robert Henri, including William Glackens and Maurice Prendergast, his closest affinity is with the Spanish painter Joaquín Sorolla who painted brilliant colour-saturated scenes of the Valencian coast. He was certainly aware of, and probably attended, the sensational exhibition of Sorolla's work held at the Hispanic Society in New York City from February until March 1909. Of the over 350 paintings exhibited, almost half were light-filled canvases of the shore. More than one hundred and fifty thousand people visited the exhibition, often standing for long lines in the cold, and twenty thousand catalogues were sold. In 1918 an American critic tried to minimise the influence of the Spanish artist on Potthast, yet only succeeded in stressing their similarities, when he wrote that Potthast's "beach scenes, which have brought him deserved reputation, have the same colour and light and movement of life and air that made Sorolla famous, and while they are reminiscent in subject, and now and then in treatment of the great Spaniard, they are none the less spontaneous and individual."
Potthast's ocean-side scenes portray the middle and lower-middle classes, native-born Americans and the more recent immigrant arrivals, who shared in the ocean shore a common ground of pleasure. The sand and surf of the coast, as well as the newly created parks within New York City, allowed a release from the pressures of urban stress. By 1900 several hundred thousand visitors journeyed to Coney Island on Sunday afternoon. Potthast's paintings portray mostly woman and children for whom the steamer, railroad, electric trolley car, and finally the subway, made the beach more accessible. The man of the family, working five and a half or six days a week, seldom appears in Potthast's canvases, which were more likely painted during the less crowded weekdays which allowed the artist at least a modicum of privacy.
Although he often painted figures bathing in the sea, Potthast's earlier seaside paintings frequently show the indolent leisure of figures along the shore. "The opportunity to bathe in the Old Ocean is not the only attraction of the beach" noted a 1906 description of Coney Island, "Great crowds find rest and recreation in sitting on the sands and enjoying the cool breezes, as they gaze across the sea at passing vessels." In Beach Scene the anonymous faces are rendered with broad brushstrokes-Potthast's extraordinary manipulation of paint, it has been eloquently observed, creates "passages of liquid transparency and crusty light-charged impasto underlying a style which is essentially devoid of formula and rich in effects of crisp and telling immediacy." The gestures of the figures reveal an intimate observation of the social activities of the shores. A child with his bucket is digging in the sand, figures are playing cards, a young bather is drying her hair, groups of people are conversing, while in the distance is seen a balloon vendor, a favourite subject for Potthast. As a contemporary reviewer noted, "There are few clouds on Potthast's horizon and when they do move over his azure skies, they are creamy white or rose color. He is a painter of the 'joy of life,' of 'summer and sun,' and his art is distinctly inspiring."
Kenneth W. Maddox