Ever pretty navy blue prom, bridesmaid, New Years dress size 16

very pretty navy blue formal type of long dress. I bought it for a wedding and did not wear it. zipper back? Sequin and embroidered leaves. this dress is all navy, I could not get a good picture, no silver. I belive they call the bottom a mermaid bottom. it is lined. Measures 36 inch waist, it says its an 18, but I think it fits more like a 16 or a small 18. Very classy dress!