Piet Mondrian first treated the theme of the sea in naturalistic works of 1909–11, during lengthy sojourns on the coast of Dutch Zeeland. He then assimilated and adapted the Cubism of Pablo Picasso and Georges Braquein Paris soon after his arrival there in the winter of 1911–12. In the summer of 1914 he returned to the Netherlands and probably in the following war years worked on the studies of the sea. The oval format and grid structure used in these works are devices derived from Cubism. They serve respectively to resolve the problem of the compositional interference of the corners and to organize and unify the picture’s elements. For Mondrian the horizontal-vertical arrangement did not have an exclusively pictorial function, as it did for the Cubists, but carried mystical implications. He viewed the horizontal and vertical as basic oppositional principles that could interact to produce a union symbolizing a state of universal harmony. Although Mondrian’s source exists in the natural world, the signs for this source have been reduced to their most essential pictorial form. The strokes are determined by their structural function rather than their descriptive potential, and there is no sense of perspectival recession despite the atmospheric texture of the gouache highlighting, which evokes the reflection of light on water and defines planar surfaces.