This might be your best one yet. Even though it does show less "skin" compared to some of the other pieces of her, she still looks damn impressive.
How you composed not only Sonia, but everything else, intrigues me. You may have snapped a picture of a patch of blue sky, but the colors of it seem blend in very well to the aqua-marine ocean and the warm-to-spicy colors of the subject herself.
I also do not have to roll my eyes at the proportions. I normally never do in your case, but her bust and her hips look proportional enough to be taken a little back from the pin-up mood and more into a romantic feeling that even us perverts can relate to.