I have this problem of long exposure in harsh light. This in a lake side where I wanted to get that silky movement of water with a stone in foreground. However, since the daylight was harsh my images were over exposed and much of the details were lost. How should I get that silky look of water with long exposure in a harsh daylight?
You can either change the aperture to a smaller value, but this might not be enough, so you would need to use a ND filter which will reduce the intensity of the light, thus allowing you to use a longer shutter speed and still achieve a good picture.
I would recommend using a 10-stop ND filter to cut the amount of light entering the lens. It works wonders :-)