Not sure about the void at the bottom. I think this would be a better, if more conventional, picture with a tighter crop. Good sky and a nice tight silhoutte
I really feel there is too much foreground here. Had this been a non-silhouette type shot with a lot od detail in the foreground that would be fine. But with this being a silhouette image - which I find meets the challenge well, the dark foreground just creates a lot of empty space. Aside from cropping off the bottom, I would suggest straightening the horizon also.
On the plus side, the colors in the sky and water are wonderful. The placement of your subject is also nice being off centered.