The lighting is flat, try shooting when the sun is out, this should help pop some life into the image. (Alternatively, try adjusting the contrast digitally.) A low sun early in the morning or later in the evening might give you interesting results.
A more important objection I have to the image is that there doesn't seem to be any natural point of focus. With the horizon in the centre, the water and the sky are given equal importance, but both of these areas are equally empty... And the land takes too small a portion of the image to really show what's there.