"CAN WE capsize again?" my daughter asked, her voice full of excitement and joy. It's nice to hear excitement and joy in the voice of your 13-year-old. It makes you think maybe she's not a bored, sarcastic teenager after all, but someone almost unrecognizable, someone filled with joie de vivre instead of the "blahs."

I was feeling pretty joyous myself as I stood on the dock at Belle Haven Marina, just one mile south of Old Town Alexandria. It seemed we had solved our problem of what to do with our teenager for the summer. My daughter hadn't wanted to go to sleep-away camp this year. She'd be too far away from too many friends and might miss something. For about a month, hanging out at the pool was just fine. When she came home from the pool, she'd be on the phone or the Internet to make sure no one lost touch in those tedious hours they have to spend at home. I didn't mind. Except for the Internet, it was much like the lazy summers I remembered growing up.

But then one friend got sunburned and another got swimmer's ear. Suddenly they wanted to spend their days cruising the mall. When I conferred with other mothers for advice, my friend Winnie had a winning idea. "Try sailing camp," she said. Her daughter, also 13, had gone for three years to the Washington Sailing Marina, where she had learned to sail and to windsurf. "Sailing is a wonderful thing for them to learn at this age," Winnie said. "They want to be independent, but they're not old enough to drive. Sailing lets them master a skill all their own."

I immediately called the Washington Sailing Marina, but all-day sailing is for families who plan ahead. It was full. Still, it was too good an idea to give up on, and Winnie had mentioned that they had half-day classes at the Belle Haven Marina, a little further down river. I broached the subject with Laura and she was willing to do it -- but only if her two friends could go, too.

I knew the odds were against me, but I'd seen one Gap store too many and persevered. Luckily, Belle Haven had room for three students the very next week.

It's hard to imagine a more picturesque spot than Belle Haven Marina. The Potomac stretches itself magnificently here, allowing seafaring ships to come up-river and pass under the Wilson Bridge. But the bridge, with its traffic and noise, is far in the distance. Even National Airport seems far away. The planes are up there, of course, but they don't assault you with bone-rattling ferocity like they do at the Washington Sailing Marina, which, unfortunately for all-day sailors, abuts the airport.

No, here things are quiet and peaceful. Everyone seems calm and relaxed as they gather by a picnic table in the blazing sun. The instructors are mostly college-aged men and women, the youngest a senior at Gonzaga. They are tan and barefoot. Most have been students at this marina in past years.

"That's what happens," says George Stevens, president and owner, "They start taking lessons and just keep coming back year after year. Eventually we give them a job."

On the fourth day of the weeklong camp they practice capsizing, and I decide to stay and watch the fun. I am very unobtrusive as only Secret Service agents and mothers of 13-year-old girls know how to be. The day starts with a brief lesson on the dock. The first rule after capsizing is to make sure your partner is okay. Then swim around and grab the dagger-board (it sticks down through the bottom of the boat). Put your weight on it; and slowly the water will drain out of the sail and the sunfish, a pretty little boat with a multi-colored sail, will right itself and pop upright in the water. Then you climb aboard.

Armed with their new knowledge and full of confidence, the young sailors proceed to rig their sunfish (put on the mast, sail, rudder and dagger-board) and maneuver out into the harbor. Looking like a flock of overgrown butterflies, the sunfish manage to avoid the big boats at anchor and head out to the open water. I'm impressed with their skill.

Four of the advanced students (kids who have come for a month or more) go out with an instructor on a 19-foot Flying Scot. The youngest students, two 8-year-olds, also get their own instructor in a sunfish. All the others, like my daughter and her two friends, are out in sunfish by themselves. The instructors follow in kayaks.

I am uncharacteristically calm when my daughter and her friends purposely capsize the boat. The brightly colored sail tips precariously and falls. The girls slide off into the Potomac and bob up and down in their life jackets.

I stifle the urge to wave my arms and shout for help. The kayak is close by, watching and giving instructions if needed. Soon the girls are back on the sunfish, crowing, "We did it!" I cheer silently from the dock.

"All right, everybody, sail up-wind," the instructor yells from her kayak. In case they don't understand this nautical term, she points. "That way." Slowly, three or four of the sunfish start to move in the right direction. Two are so close to each other I don't see how they can avoid a collision. They don't. They collide, their sails momentarily wrapped around each other. One girl slides off into the water. I hear her giggling.

Zac McNamara yells from shore at the culprits, two boys: "If you do that again, you're out of the water for the rest of the day. You can sail better than that." McNamara, an instructor for many years at Belle Haven, looks at me and grins. "That collision was on purpose," he said. "Luckily the sunfish are fairly benign. But once in a while you can pinch a finger if you're not careful." The girl climbs back on her sunfish and the boys, evidently chastened, sail off in a different direction.

Later I ask the girls if they were scared. "Oh, no. It was fun," they said. They are Marie and Francesca, 13 and 14, both of Alexandria. One is a new sailor and one came for a week last year. I ask the novice how she likes sailing. "It's kinda hard when you're stuck in irons," Marie says. When I look puzzled, she explains, "That's when you can't move because you can't catch the wind in your sail. But I like it," she continues, "You feel really independent."

Back in the car, my daughter and her friends chatter happily about plans to take another sailing class next summer or perhaps during weekends this fall. It's a hot day, but the thought of being on the Potomac on a crisp September morning gives me a shiver of anticipation. Thanks to sailing camp, we are out of the irons of summer and sailing full speed into autumn.

BELLE HAVEN MARINA -- 1 Belle Haven Rd., off the George Washington Parkway, Alexandria. 703/768-0018. Fifteen-hour basic sailing course for youth ($92) has concluded for the summer, but registration and gift certificates for next summer's classes are available now. Weekend windsurfing, a four-hour course ($70), is available through October. Weekend cruising course for youths and adults, Saturdays and Sundays, 9:30 a.m. to 5 p.m. ($315), is available through October. Private sailing instruction is $40 per hour.

WASHINGTON SAILING MARINA -- 1 Marina Drive off the George Washington Parkway, Alexandria. 703/548-9027. The marina's 32.5 hour basic sailing for youth course ($165) has concluded for the summer, but weekend basic keelboat sailing courses for youths and adults are offered Saturdays and Sundays, 9:30 to 4 for $210, through Oct. 17. Family rates are available.

ANNAPOLIS SAILING SCHOOL -- 601 Sixth St., Annapolis. 800/638-9192. The school offers three- and five-day Kidship basic sailing courses ($275-$350) that have concluded for the summer, but weekend youth basic courses are available Saturdays and Sundays from 9 to 4 for $180, through Oct. 31. A five-day family flotilla cruising course, Mondays through Fridays, $1,960 for 30-foot boat (2 to 6 people), $2,165 for 37-foot boat (also 2 to 6 people), is offered through Sept. 10.

CHESAPEAKE SAILING SCHOOL -- 7074 Bembe Beach Rd., Annapolis. 800/966-0032. The five-day basic sailing courses for 12- to 17-year-olds have concluded for the summer, but the school still offers some weekend courses and family programs for parents and children, including a three-day vacation cruising course for two adults and up to four children (plus staff captain), $1,600 per family, through September; and a five-day vacation cruising course for two adults and up to four children (plus staff captain), $2,250 per family, through September. Half-day (four-hour) instruction on a 22-foot boat for up to three people (including at least one adult) is $150 and is offered through Oct. 24.