A lot of the difficulty with sea painting comes from the fact that it's constantly moving. But understanding the elements, such as the different types of sea foam, helps simplify what you're looking at.
Surface foam floats on the water, moving up and down as the wave passes underneath it. If you have trouble visualizing this, think of the wave as energy that moves through the water causing ripples, like when you flick a blanket on the edge and a ripple moves through the fabric.
Surface foam typically has holes in it, rather than being large, solid area of foam. This pattern can be used to lead a viewer's eye through the composition, as well as to create a feeling of movement or height in a wave.
Wave foam is created when the weight of water at the top of a wave becomes too heavy, and it breaks, or falls over, at the crest of the wave. The water becomes aerated, creating foam.
