Answer
I think a vivid dream becomes lucid when we realize we have some type of control in the dream. For example, I had a dream where I was standing by a lagoon and I dove in after something. When I was underwater, I stopped for a moment and panicked then realized that I was dreaming therfore I could breath and did not have to worry about holding my breath.Nothing exciting happened as I felt coming to the realization that I could be under water and breath was exciting enough! I had the best time swimming around without a care. The water was merky and there were old stumps,water plants -it was so real. I could feel the pressure of the water while swimming against it.