In elomi I wear a 38H (US 38K) (underbust 37.5 - Bust 49). So I bought this in a size 40 cause I wanted it to be comfortable and not confining. And as per the bra rule, if you go up a band size you're suppose to go down a cup size. Therefore, I bought a 40GG. It fit great, except the bra part was to small and the underwires landed in a bad spot. So I would advise going up a band size but keeping your normal cup size. So I just bought another one in a size 40H (US 40K) for a better fit. Love how long it is with the option to make shorter with the side ties. I am a chunky chic and this looks good on me ) Haven't got to swim in it yet cause it got cold ( So I can't tell anything about how it fits when it's wet. I do recommend this if you get the right size.

UPDATE - Worn in pool for hours on multiple occasions now - Great fit, support and comfort!! It stays where you put it!

HOW TO PUT THIS ON WITHOUT GETTING STABBED BY UNDERWIRES - Put it on before bottoms - Stand in front of mirror and see proper positioning of back bra band.  - STEP into this and pull up almost to waist - Smooth and fasten hooks and eyes - Pull up the rest of the way - Adjust girls - Easy peasy !

Take OFF WHILE WET - Remove straps from shoulders- Reach back and undo hooks and eyes - Grab bottom sides of underwires and pull DOWN -  Step out of.