Hi Frank,
Symmetry can often be an important part of landscape photography, particularly when you're photographing quiet scenes like this. As the eye scans the picture from left to right, it's often nice to know that there is balance. There's a starting point, a gentle statement and a conclusion.
For me, this picture lacks that balance. Part of the problem is that this sky in the left of the picture is rather bright and yet to the right of the picture it's dark.
You have two options here; one is to turn the photograph into a panoramic format, and in the process try to include the sunset and the sky to the left of the scene. At a guess, though, this is going to be nearly impossible to do without including a lot more of the scene that you don't really need.
Another option though, is to have look at cropping this image to a square format. What I like about this idea is that it enhances the slenderness of the yachts, while at the same time making the gradient across the sky less noticeable.
About the only other thing I'd do is to go into the Curves panel and lighten the image a hint, by pushing out the middle of the curve.
Keep exploring Williamstown with your camera; it's a great corner of the world which deserves some more attention. Cheers, Anthony.
Image Doctor's edited version
