I was feeling pretty gloomy and dumb a couple days ago ... So, yeah, it's rather reasonable my Terragen 2 picture here is pretty similar.
I am not perfectly satisfied with this result. The water, I think, looks the worst. This took around 2 hours to render, so it shouldn't be too hard to render this again.
Try reducing the wave size. But with the stormy look, increasing the wave scale and size might look good.