Hey George,
Not sure how I have missed this for the last few days. These are my thoughts.
James
Composition/use of frame space - This is a great composition, and the more I see, the more I like. The currents are beautiful, and I like the addition of the moon - though I wish it weren't blown out (LOL, you can always drop one in later!). I go back and forth with the debris in the lower quarter of the frame - wondering if it should be cloned out or not. I think you did right by not touching it, but I am wondering how the shot would look from a few feet to the left.
Colors/White Balance - The colors are the thing about the photograph that I really like as well. The blue-green rushing waters are beautiful.
Exposure - You nailed the exposure beautifully. This is a trick shot. The moon, honestly, if it was slightly past sunset was not going to be exposed properly no matter what you did. There is just too much of a range between the foreground and it.
Creative use of Aperture/Shutter - This is definitely different. The freezing of the water in what I am assuming is twilight, is really beautifully done.
Emotion - LOL, I just feel cold when I see this image. That says something!
Post Processing - I already covered the few small areas about this image that I might consider tweeking.
Anyway, sorry you did not get any feedback on this shot earlier. I really like it a lot. Thanks for sharing.
James