By further analyzing the seascapes Manet painted prior to his plein air work at Arcachon, we can better appreciate the transition of his brushstrokes in 1871. For example,
Steamboat Leaving Boulogne, also painted in 1864, conveys even less motion than The Battle of the 
U.S.S. “Kearsarge” and the C.S.S. “Alabama.” In this piece, Manet uses only smooth, horizontal strokes of green and blue with almost no white to portray the boats’ movement through the water. The sailboats appear as if they were placed gently on top of the water, because the strokes around them are the same color as the rest of the sea and do not extend off the main flat surface at all. Rather than using sweeping or white strokes to indicate waves splashing up the boat, Manet’s level strokes give a sense of lasting stillness. The scene does not capture a moment in time but a still life of stagnant water. Instead of using the steamboat as a source of energy to drive the scene, the artist uses strokes to depict the boat’s wake that blend into the rest of the sea. The wake lacks definition, persisting as a stretch of light green, horizontal strokes until the very edge of the boat, at which point Manet incorporates white. But even here, the wake is only a trickle. Instead of splattering up on the back of the boat, the waves appear as flat, unanimated strokes.
In his 1868 painting, The Steamboat, Seascape with Porpoises, Manet’s brushstrokes allow us to evidence a slight transition from four years earlier. To more effectively capture the wake of his boats, Manet incorporates white around the edges of the two steamboats as he does in Sailing Ships at Sea, painted in the same year. He also includes more airy strokes at the back of the large crafts that bring more motion to the scene than the entirely horizontal sea of his 1864 pieces. However, the scene still appears mostly stagnant, with the majority of the strokes still thick, horizontal lines of one color. Though both steamboats have a more billowy wake than the boats of Steamboat Leaving Boulogne or The Battle of the U.S.S. “Kearsarge” and the C.S.S.”Alabama,” the waves do not splash against the sides of the boat but rather appear disconnected from the crafts as if the boats have failed to generate action. Furthermore, the sailboat on the right side of the painting does not have a wake at all. Rather than creating motion by incorporating staccato strokes or clashing colors, The Steamboat, like Manet’s earlier seascapes, features an unbroken, glasslike sea that contrasts with his post-1871 pieces.
Manet, Edouard. Steamboat Leaving Boulogne. 1864. The Art Institute of Chicago, Chicago.
Manet, Edouard. The Steamboat, Seascape With Porpoises . 1868. Philadelphia Museum of Art, Philadelphia.