catch the wave; Could surfing be the new yoga.

Byline: Abigail Walch

For some, it's a slight jiggle under the arm. For others, a dimply pillow on the back of the thigh. For me, it's a gentle roll, one I could pinch or my cat would knead, right below my navel. Almost everyone has one, a stubborn body part that won't firm up no matter how low your weight drops or how hard you work out. I had all but given up on my soft spot until recently, when, for the first time since high school, I gazed down and saw nothing. My Botticelli belly had disappeared, replaced by abs that were toned, hard, even a bit . . . cut. No nips, tucks, or marathon Abdomenizer sessions-I had been to surf camp, a seven-day retreat where the daily schedule is dictated by the tides.

It's not as if I thought, I want flat abs; I should surf. I kept hearing about women like me-young, landlocked professionals-who listed surfing as a hobby alongside yoga and dinner parties and knitting. They seemed cool in an I-can-do-anything sort of way. "Girls who know how to fix a flat tire, play the drums, or paddle out and rip-it gives them an edge," says Izzy Tihanyi, founder of Surf Diva, the world's first girls-only surf school, based in La Jolla, California. "You're stepping across the line into the boys' turf." Izzy counts Carolyn Murphy-"she really rips"-among the thousands of people she has taught to surf over the past nine years, and lists Minnie Driver, Juicy Couture designer Pamela Skaist-Levy, and Urban Decay's cofounder Wende Zomnir as surf buddies. Surfing has come a long way since the iconic sixties film The Endless Summer, shedding its scruffy beach-boy image for a sophisticated allure. This spring, I decided I should-and would-learn to surf.

The difference between surfing against the backdrop of a ritzy resort versus a place stripped bare can be compared to eating a lobster roll at a five-star restaurant or biting into one at an oceanside clam shack. One feels pretentious, the other authentic, which is why I ended up at Vista Guapa, a coed surf camp in Jaco, Costa Rica. The whole work-for-thrills mantra of surfing spills over into the camp lifestyle: Vista Guapa's three bungalows have a stunning view of the Pacific Ocean, which you can enjoy after hiking up a short but steep hill. There are no TVs and no phones and certainly no hairdryers in the light and airy cabanas, but in-room massages soothe paddled-out shoulders.

As my first lesson drew near, I began to have serious doubts. Not only had I never surfed before, but I don't ski, snowboard, windsurf, or practice any other balance-required sport. Still, I was not a complete surfing naif: A few weeks before heading to Costa Rica, I had enlisted the help of Paul Frediani, a Laird Hamilton-esque surfer who has trained the U.S. Surfing Federation team and recently created the new Equinox class Surf Flex. Paul had me practice pop-ups-springing from a push-up position to standing, as you do on a surfboard-and lift weights while kneeling on a stability ball to strengthen my upper body and core muscles, particularly my stomach. Whether paddling, standing, or sitting on the board waiting for the next wave, surfers are constantly engaging-and toning-their abs, Paul explained. After a few sessions he delivered the fateful assessment: "You're flexible but not all that stable." (A more pithy and accurate diagnosis than any shrink has ever offered.)

I thought about the push-ups Paul had suggested I do, but didn't, as I watched the other "campers" paddle out. That week's group included two women in their early 30s, financial types, who live in Los Angeles and own surfboards (but until camp, didn't know exactly what to do with them); a family of snowboarders from Wyoming; and a young woman from Hawaii who was deft enough to surf the early-morning session, when the instructors search the coast for the day's biggest waves.

As the complete rookie in the group, I was paired with local master Alvaro Solano, a ...