getting a smoke effects in the water, you have to slow your shutter speed but you also have to consider the exposure as a whole.
I found that the exposure here is not well balance. My suggestion here are:
1. Use CPL to cut the reflections on the water and this will also slower your shutter.
2. Full ND and Grad ND, Full ND will slower your shutter (-? stop) and grad will balance your exposure in the sky and the ground level.
2. Sunset Filters or Grad Blue Filter to have more dramatic skies.
just my personal suggestions......... thanks for sharing.