SENIORS : ‘Do-Si-Do’ : With 12 clubs and more than 1,000 members, the county is a hotbed of square dancing.

Seniors, want to expand your social life? Bored with walking laps at the mall? You can’t beat square dancing for inexpensive, fun exercise. With 12 clubs totaling more than 1,000 members, Ventura County is a hotbed of square dancing. In fact, square dancing is the official folk dance of California, according to Roy Northup of Ventura, president of Bachelors ‘N Bachelorettes.

“But I’m single,” you say, “and I don’t know how to square dance.”

No problem.

Bachelors ‘N Bachelorettes, an international singles square dance club, has chapters in Ventura and Thousand Oaks. BNBs, as it’s called, also accepts couples, but it is designed for single dancers--those who arrive without a partner.

“I got a divorce 13 years ago and didn’t know what I was going to do,” said Margaret Westendorf, who is in her early 50s. “A friend suggested square dancing. I’m still single, still dancing and having a great time.”

The remaining clubs will try to help you find a dance partner during the first two to three weeks of lessons. After that, however, you must bring your own to continue.

Dance partners John Eslick and Irma Hambly graduated from the Conejo Thumpers class three years ago. According to Eslick, some couples clubs such as the “Pi R Squares” accept singles and try to help them find a partner. Hambly said, “That’s because most widows and widowers don’t look upon themselves as single. They just don’t have a partner.”

Early in September, all the county clubs will begin weekly square dance classes that continue for nine months. Clubs meet on different nights, which allows visitation between groups and makes it possible for people such as 20-year-old Steve Avery to belong to clubs in four cities.

Avery completed classes last year. “There are quite a few retired people involved,” he said. In fact, more than half of the county’s club members are over 55. The rest are in their 30s and 40s.

If your working knowledge of square dancing stems from fifth-grade P.E., as mine does, let’s learn together:

“Sets” or squares of eight dancers perform a series of steps according to the “caller,” who sings instructions, tells jokes and entertains the crowd.

After six months of lessons, “mainstream level” dancers know the first 40 calls or dance moves in the Dictionary of Square Dance Calls and Moves, including the familiar “promenade” and “do-si-do.” Graduates of the standard nine-month classes reach “plus level.” With about 74 moves under their belts, they can perform complex moves such as “relay the deucey,” which is done to 48 musical beats.

To keep things interesting, clubs also hold special dance events. A mystery bus trip recently took BNBs to a club in Orange County. Westendorf, president of the Thousand Oaks BNB, said members keep on learning at “quarterly dances” held by all the clubs. Four times a year, California’s 22,000 square dancers learn a new “tip” or call.

It costs about $3 to dance the night away. But in other ways square dancing is big business. Besides specially designed club name tags, most people buy “swingers.” These collections of badges that swing beneath the name plate on small chains indicate past and current club offices held, and other clubs visited throughout the world. According to caller Darren Gallina, people square dance all over the world. Even in Japan, the calls are in English.

For hard-core enthusiasts there are newsletters, Windbreaker jackets and even RV square dance clubs. Many attend square dance conventions where they can buy gag-tags with nicknames or slogans, license plate frames, car decals and dance clothes.

Nevertheless, most people purchase their wardrobe from square dance apparel shops. Women wear colorful, fitted dresses with short, full skirts and puffed sleeves. Many prefer dance shoes with a wide, pump heel and an ankle strap to keep them in place. Men often sport cowboy boots and a string tie or neckerchief over a fitted Western shirt.

Rosalie Fitch is a single member of two clubs in Oxnard and Ventura. At 59, she has been dancing for two years. “I’m proud that I’m in condition to still do it.” Her two granddaughters, ages 10 and 11, have also completed the classes. “They’ll call me up and ask, ‘Nana, you goin’ square dancing tonight?’ ”

Fitch picks them up, and away they “do-si-do.”

* WHERE AND WHEN: Beginning Sept. 6, the square dance clubs in Ventura County will offer nine-month classes. Call for details

* Agoura: Buckles ‘N Bows. (818) 346-6236.

* Oxnard: Romping Stompers. (805) 983-8044.

* Point Hueneme: Starlighters. (805) 486-3674.

* Thousand Oaks: Bachelors ‘N’ Bachelorettes. (805) 495-9814.

* Newbury Park: Conejo Thumpers. (805) 497-4756; “Pi R Squares.” (805) 523-7675.

* Camarillo: Ripsnorters. (805) 983-4074.

* Ventura: Bachelors ‘N’ Bachelorettes. (805) 495-6658.

* Simi Valley: Boots ‘N’ Slippers. (818) 594-0213; Happy Squares. (805) 583-4663.

* Somis: Valley Stars. (805) 495-5020.

* Santa Paula: Road Runners. (805) 525-8450.