Change Mode to LAB COLOR - next go to the channels panel and select the Lightness channel only. Now apply the Unsharpen Mask filter to that channel only - you may be quite aggressive without altering color or the image too bady. When finished - change mode back to RGB.
Applied Contrast Mask -
Create a duplicate of your image. In the Layer panel, double
click on the new copy and then apply Desaturate to it, then invert.
Change the type from normal to Overlay and finally, apply the gaussian
blur filter to the final result. Adjust the blur to get the best
picture. This will bring a bit more contrast out of the image.
Finally, I spotted the image by removing a couple of dust specs on the pier.