THE bathing suit market is tanking. But this is a good thing.

PHOTOS: Suitable One-Pieces

The tank is the new suit, taking the plunge into waters of modesty. But what is modest today (do you really want to see that much of Britney?) was racy in the day, and the one-piece has had many lives. Blame Katy Perry among others for the taste in ’50s pin-up retro, and maybe Paris Hilton for the revival of the sexy ’70s Bain de Soleil numbers. (Burger commercials will never be the same.)

Sure, the one-piece is better for posing than sunning, but girls like Sienna Miller and Lady Gaga know that’s where it’s at anyway.