Long exposures with water are intriguing. This is a picture Jim took in Brugge, Belgium with a 15 second exposure. Look how smooth and glass-like the canal is. Jim now carries with him an 8-f/stop neutral density filter, so if it's not dark enough to use a long exposure, the ND filter allows him to extend the exposure time. He also had to lower the ISO to 100, and his aperture was f/22.