Everything looks a little different under water. It accounts on how deep you are, how clear the water is. If the sun blast or clouds cover the sky and if the ocean is calm or ruff. What is farther away is not so clearly seen and seams sort of fuzzed up looking through the water.
For this picture I imagined a snorkel tour in our big Mayan Reef just below the surface so daylight comes through the turquoise Caribbean water. It is a sunny day so there is lots of light. A snorkeler has his diving light pointed at some plants what revealed the beautiful colors.
I'm still experimenting and learning my new program ArtRage. Most of the painting was done in it but I transferred it to Digital Image for a final touch.