This is a tonal exercise. Begin with a drawing. Divide your paper to make thumbnail size areas, either 6 or 9. Place your horizon line roughly two thirds of the way up the thumbnail. Than draw triangles for the yachts, remembering to make them smaller as they get further in the distance. Stagger them.
Now, paint one medium tone around the triangles. Next paint distance hills on the horizon. The application of the tone should be the same because the second wash will be darker. The top of the sky and the sea can be a second band of colour, both will be darker. If the paper permits, you can lift out a reflection with a damp brush.
Tip: In order to keep an even wash, continue to load your brush, maintaining the bead of paint.
First divide your paper into 6 to 9 segments. If you are unsure of your drawing, trace an image of appropriate size. The point of this exercise is to develop the background. Here I’ve demonstrated a horse with a rider. You can build either an abstract background or one with some distinct detail. Prepare your background and complete by the addition of water with a wet brush to gently merge the color. Don’t scrub and use a minimum amount of water. With a detailed background, wait for the paper to be completely dry and then go over again to enhance the detail. Also, once it’s dried, you can put highlights on the image.
Tip: Experiment with trying to use only primary colours.