Great decision to make this a monochromatic image. The absence of color focuses your attention on the composition, the balance of light and dark, and repetition (surf/ripples in sand, mountains/foreground rocks, ocean/beach). A lot of thought went into this picture, and it would work just as well as a photograph, a drawing or print. Only quibble might be a slight disconnect between the body language of the horse and rider: the horse is ambling but the rider seems to be cantering/galloping. A more erect posture there might better fit the mood. But that's nitpicking. Nicely done.