First I used Photoshop CS 2 clone tool to remove some of the dust specks that were in the sky. Then I used the Unsharp Mask Filter to sharpen the photo which introduced some noise in the sky. I duplicated the photo into a new layer and used the Noise Removal Filter to remove the noise. Because the Noise Removal Filter blurred the photo I created a mask to only show the top part of the layer where I removed the noise. This way the water is now a bit more sharp and the sky has no/little noise.