Judy, absolutely stunning, the best sunset you have posted yet to me. It is interesting that you use such large apertures.
The photos look great, just not the usual.
I always just shoot at least f8 for landscapes, just seems intuitive.
Your shots make me re-think this, it looks great at f4.5 as there is nothing in the foreground but still,
I rarely view landscape photo's with apertures like yours.
A great photo and a good learning experience.
I usually start out at f8 when the sky is still bright in a sunset but at the tail end when it's dark I go wider as I am hand-holding, usually on a floating dock, and I don't like to use higher ISO than 400 unless I have to. It seems to work fine even at f4. Lens is 24 - 105 f4.