That top has to be just for show because there’s no way she’s swimming in that thing if she expects it to stay on.
Marika Fruscio’s 37G-25-37 frame busts out of just about anything she can find to put on, so in her case, she just wears as little as possible. It does seem to make things quite easier.
She’s far from just a big-breasted non-swimmer. She’s got some pretty incredible photos too that serve as more proof of her being anti-clothing.