Mermaid dress...hoop or crinoline??

I would try the crinoline. This doesn't apply to my wedding gown, but I am a huge nerd and dress up for the renaissance faire every year. One of my gowns requires a hoop skirt and they are such a pain. Sitting is always an ordeal and if a ring snaps it will look like a section of the gown has deflated. Crinoline will be much more comfortable with not only sitting, but movement and dancing too. Try Amazon for a crinoline skirt. I have seen very affordable ones on there and if you don't like the way it looks, you can return it. Just make sure to check that the vendor allows returns. I use Amazon for so many things and have never had a problem.

Just to add, I see "me" and "not me" at the bottom of your post. I am assuming you posted photos, but they aren't showing.

My daughter is wearing a layered tulle ball gown and we went through the same dilemma. We ordered 3 different slips from Amazon and tried them all on with her dress then returned the 2 we won’t be using. FWIW, she went with the hoop because it gives her legs room to move under the dress. The crinoline would collapse against her, was very hot, and would require fluffing throughout the night. Those might not be concerns with a fit and flare though. Just try some on and see which one gives you the look, feel, and comfort you’re looking for.

I think your dress would work with a crinoline slip.. Check out Amazon and order a few that have free returns. Best of luck - your dress is beautiful!!