4. Add the Sun and Water
Place a circular sun in the lower part of the sky. Suggest the surface of the water with curvy lines placed at random, both near the boat and in the distance. Put sets of diagonal lines inside the boat to show its riblike structure. Fill in a name of your choice on the side or back surface. Form the sea wall with parallel horizontal lines between the posts. Make a bunch of jagged or spiky shapes for tufts of grass, then add a few large ovals as rocks.