Using an airbrush to create artistic paintings is a skill that can only be mastered with much practice. Familiarity with your airbrush is require so that you know how much pressure is required to produce different types of lines. Airbrushing natural wonders such as an ocean wave is a good way to gain practice with your airbrush. This subject is also an easy start to artistic airbrushing because waves do not have one set way that they must appear.
Using your deepest intended tone, airbrush the shape of the wave curling upward from the body of the water. The shape of the wave might form a "C"-shaped curl. A good starting point for your deep colour would be a medium blue-green.
Add the body of the wave extending across from the initial "C" shaped line. This will dictate the size of the wave and the perspective of the painting. If you pull the body of the wave toward the viewer, it should get larger. If you push the body of the wave away from the viewer, it will get smaller. After airbrushing the body, you will have the basic shape of your wave.
Using a significantly lighter tone, paint highlights onto the wave's body. The colour should be deepest near the middle of the wave and become lighter near the edges.
Paint the white water along the very edges of the wave using a very light blue or even white if you are going for high contrast. The white water shows the intensity of the wave; if you would like your wave to be high-intensity, add more white water. You can also pull the light tone up and away from the top of the wave to show light mist coming off of it.
Airbrush the body of the water around the wave to finish the painting. The body of water should be painted with the deep tone that you used earlier to paint the shape of the wave. Depending on the size of your wave, the canvas might not have room for a body of water, if this is so, omit this step.
If you want further airbrush practice, paint the sky and any surrounding land features before painting in your waves. Allow them to dry thoroughly before continuing so that the paints do not mix.