nice composition. i like that you kept the distant one in the background, softened by the narrow dof. i like the colors of the whole scene, not just the browns of the rust, but also the soft green-blue of the sea in the background.
the wonderful thing about rust is definitely its color and texture. to bring that out, making the colors rich, you might try increasing the contrast. high contrast is very effective on rust shots. i played with the contrast on your photo and found that it responds very well to it. give it a try.
