Andy, I like the composition and the idea behind the shot. However, I don’t think that using HDR has worked very well here. I suspect that if you look at the shadow areas, they are just very noisy, rather than containing any detail worth recovering. Also, the sky and water have become very flat and lifeless due to the HDR processing.
I would recommend a manual blend of 2 exposures, one for the sky, the other perhaps 1 stop brighter than that for the foreground. Layer them up in Photoshop, and use a gradient mask to blend. I have a feeling the result will look a lot more natural, and it might actually enhance the play of light on the foreground.