Earth, water, air - fits the challenge like a glove. Will not score well because there is not much of interest to attract the eye. A seagull, dog, human would help. And most people expect blue water and blue sky.
perfect example of the rule of thirds. However, no main subject to grab the attention in this picture. Also color/contrast could be a little better. The sky seems too grey for a winning picture. Maybe UV or polorizing filter would help some.
the hue seems off. everything seems slightly purple. even the brown and green have hints of purple.
on a side note. from a distance it looks like a flag of an unknown country with the three sections being equal. almost like three stripes. just a random thought.