Thanks. I've actually never really thought smoothness and cleanness to be strong points of my images. I try to keep the ISO as low as possible at all times, but my processing work flow involves some contrast and saturation adjustments that often bring out noise even in images shot at ISO 100. I do use noise removal software (Neat Image) when necessary. In this particular image, my processing resulted in noticeable noise in the water and sky, but I just blurred these areas in PS, which removed the noise while also enhancing the effect of the long exposure.
Thanks for the info, most people don't like to share their workflow . Either way, you did a great job with selective blurring. I do the same things on some of my skies as well. Usually a Gaussian blur to the entire image then create a layer mask and draw over the parts I want blurred.