I'm thinkin' it's the choice of film, but you have a lot of grain in this image. I think a slower film would have suited the situation better, enriching the color saturation and allowing more detail.
Regarding the composition, I think your horizon is off a little, although it could just be the shoreline leading my eye. Also, the horizon is nearly dissecting the image into equal halves. Have you considered taking about 15% off the top so that the horizon is at the upper third grid?
Obviously these are just my humble suggestions. I like the image quite a bit, being a sucker for sunrises and sunsets.