How the keyhole became the swimsuit’s most functional feature

Swimming laps in the wrong type of bathing suit is the swimwear equivalent of playing with fire. Sure, bikinis look great in Instagram pictures, but the minute you attempt to wear one while performing the butterfly, you run the risk of flashing your top half, bottom half, or in the case of my eighth grade pool party, both at the same time. One pieces are problematic in an entirely different way, because they fill up with water and slow down your strokes. And don’t even get me started on tankinis, which deserve their own place in the 10th circle of hell.

So what’s a burgeoning Katie Ledecky to do? Invest in a keyhole swimsuit, which I hereby declare to be the holy grail of all the fashions that are actually meant for swimming.

You know the ones I’m talking about—those ultra-chic, yet functional, one pieces that have a circular-shaped cutout right below the boobs.  We love ’em because aside from giving the girls a little bit of understated airtime, the artfully placed hole allows for water to move in and out of the suit so it won’t get stuck and make you feel like a waterlogged—albeit well dressed—pufferfish. “We’ve used a keyhole construction on the front of our Peak Suit as a way to allow water to easily flow out below the bustline, says Shannon Savage, co-founder of Left on Friday. The brand also offers a suit with a keyhole in the back, which helps keep the  straps from falling off. “We love how the keyhole became a super-functional and pretty part of both designs.”

And what’s more, they can be a good option regardless of your cup size because keyhole suits offer benefits at both ends of the spectrum. “I think any keyhole helps regardless of size,” says Savage. “It’s more important to ensure the fit of the bra is great. Your cup size, bust shape and ribcage size will impact how well a keyhole functions or not, or how much a suit will catch the water at all.”

Whether you’re swimming, sunning, or—my personal recommendation—some combination of the two (while protected with copious amounts of SPF, that is), check out our favorite spring swimwear that will be your #majorkeytosuccess, no matter what activity you wear it for.

Shop keyhole swimsuits

Athleta Piha One Piece $78

Left on Friday Peak Suit $170

Seafolly Active Keyhole Maillot One-Piece Swimsuit $152

ASOS Lost Ink Textured Keyhole Cut Out Swimsuit $57

JETS by Jessika Allen Parallels Plunge V-Neck One-Piece Swimsuit, $195

Vilebrequin Ostend Printed Keyhole One-Piece Swimsuit $295

Women's Textured Tie Front One Piece Swimsuit - Kona Sol $40

Vitamin A Alma Bodysuit $194

Solid and Striped The Kelsey $101

Skye Swimwear Olivia One Piece $90

Indigo Swimwear The Del Mer $56

L*Space Jean One Piece Suit $169

Summersalt the Swan Dive $95

Sweaty Betty the High Tide Swimsuit $120

Ready to jump in? These are the best places to swim in every state. Plus, 10 swimming pool games that are so much fun, you won’t even realize you’re working out.