I've lately been doing some experimenting with long exposures and water. Most of the examples that I've seen have been at the ocean, but I decided to give it a try in lake country. The results aren't always as dramatic, as lake water generally doesn't move as much as the crashing waves at the ocean. With a lot of patience and experimentation, I did get some results I was happy with.
The soft almost dream like surface of the water is caused by the water's movement during exposures of 30 seconds or longer. I'm looking forward to experimenting more.