Lured by the sun, the baby waves and an eye-candy surfing instructor, I found myself on Santa Monica’s postcard-perfect beach, its famous Ferris wheel and roller coaster decorating the background.

“At which point do I attach the cord to my ankle?” I asked, struggling to control my 8-foot, blue-striped board in waist-deep water.

While the question drew the stink eye of the high school friends joining me in the lesson, teacher Charlie Jinkles — a buff former Marine who served in Iraq — gamely submerged himself to attach it for me.

Yes, I like surfing. At least more than I thought I would.

A milestone birthday had arrived, and jumping from a plane, scaling Everest or learning Swahili were all much lower on my short list of ways to celebrate. Although hanging 10 in California didn’t necessarily seem like the most rational way to ring in the next four decades of my life.

After all, I could get sucked out to sea, break my nose again or end up on some distant beach looking like a dead eel in my wetsuit.

First it was Maria’s turn. She had lived in San Diego once and even brought her own wetsuit. But it had been a while. Touching the “rails,” or the edges of the board, while mounting it did her in and served as a lesson to us all.

“Okay, paddle PADDLE!” Charlie shouted at Kristen as she tried to catch her first wave.

Not bad, I thought, as I plotted how to one-up her and prove just how hip East Coast girls can be.

After encouraging my friends, laughing each time they took a spill and scanning the water for leopard sharks, it was my turn.

It’s a good thing that I grew up on Cape Cod, Mass., and am quite familiar with the sensation of a large blast of salt water up the nose while gallons shoot down the throat.

the fifth attempt I was up on the board. Short and sweet, but standing on the board nevertheless.

Now I was part of the U.S. “surf/skate” industry, a $7.22 billion market, according to the Surf Industry Manufacturers Association’s 2008 retail report, which lumps the two categories together because of their shared clientele.

That marks an 11 percent increase from 2004 and a 3.5 percent decline from 2006.

A passion for riding the waves is what fuels groups like Stoked Mentoring, a New York- and Los Angeles-based nonprofit that matches kids with mentors to learn skateboarding, snowboarding and surfing. One of its mottos is, “Falling is an opportunity to get back up.”

Our hero Charlie was headed to a Stoked event the following day.

Each time got easier as we kept in mind his board-mounting mantra of “slow is smooth and smooth is fast.”

From there, we were to paddle ahead of the crest, assume a downward-facing-dog-like position, and “pop” into a two-legged stance.

My best performance, a solid six seconds standing before flopping, was criticized for a lack of bend in the knees.

As the surfing lesson went into its second hour, I found myself relaxing and even enjoying the exploit, alternately humming the Surfaris’ “Wipe Out” and the theme song from “Hawaii Five-O.”

Charlie’s insistence that each wave provides a new and different experience from the last was indeed true. I also discovered that each one offered the gift of a new way to embarrass oneself upon the inevitable wipeout. There was the near-miss-of-the-head wipeout; the I-tried-out-for-Cirque-du-Soleil-but-didn’t-make-it spill; and the yeah-I-meant-to-do-that variety.

Suddenly, a commotion in shallower water got our attention. Maria, an emergency-room nurse in real life, found herself examining Kristen’s bent middle finger. She’d suffered a torn tendon, but persevered through the weekend — earning “street cred” with her orthopedic surgeon.

It was a much-needed break from Manhattan, to which I returned a calmer person with a broader vocabulary. “Gnarly” became my way of describing something good.

And I learned that life can begin at 40. All you have to do is go surfing.