Disclaimer: have only tried on, have not worn in water yet.
30DD/32D (29" underbust, 34" bust) purchased size XS+
XS+ is GENIUS. Usually for a band to be tight enough, the cups are too small for me. This fixed that problem!!
DOES run smaller in the band (plenty of coverage cup size wise), probably could get away with a size small as I have it set to the loosest hook (which I'm almost never able to do!)
I LOVE this silhouette. Flattering and SECURE. Padding feels substantial enough to not nip through. Love that both straps and band are adjustable without being ties (perfect for life jacket activities).
Literally about to purchase in every color. I AM SO SO SO IMPRESSED.