At one time, synchronized swimming was synonymous with Esther Williams and images of gilded costumes in entertaining water shows. Now in the aftermath of the 1984 Summer Olympics the water sport is gaining local recognition.

Following its Olympics debut, 70 girls signed up for the beginning clinics of the Northern Virginia Nereids, a 6-year-old league of Marylanders and Virginians, ranging in age from 5 to 18. The team has 36 competitors, including an eight-member travel team which has taken top awards in national competition.

"The intensity of the program is much greater," said Kristine Olson, coach of the Nereids and former synchronized swimming champion at Michigan State University. "A lot of times there was a preconceived notion that this was something to do if you didn't have speed, but (that's) been proven quite the contrary."

Synchronized swimming is a combination of gymnastics and dance performed in the water. The good athletes are graceful and precise, trying to make their movements appear effortless. Often observers think the swimmers are just standing in the water.

"In order to be a good synchronized swimmer, you have to be a strong swimmer and it's good to have a dance background," said Olson. "(The swimmers) need a great deal of flexibility and they should also have gymnastic skills."

Diana Ulrich, 15, the top competitor on the Nereids, recently placed 27th in the nation in the 12-and-over solo competition at the Senior Nationals. Ulrich, from Oxon Hill, also is an accomplished speed swimmer, gymnast, trampolinist, ballerina and cross-country runner.

Ulrich and teammates Jan Reitzeill, 17, and Amy O'Donnell, 16, perform a dynamic trio routine that came in sixth in the South Zone competition in Florida which qualified them for Senior Nationals. The eight-member team placed fourth in South Zone and 23rd in the nation.

"(My mom) used to teach me synchronized swimming before I could swim. I'd put my leg up and sink," said Ulrich, who has been talking to coaches from the West Coast in the hope of joining one of the nation's top synchronized swimming clubs.

"I like doing solo because I like getting out there and doing something on my own. But I have more fun doing the trio," said Ulrich.

In the solo routine, the swimmer must maintain synchronization with the music (there is an underwater speaker) while routines with two or more people require that the swimmers are in time with one another.

"I think it's a lot harder than speed swimming," said O'Donnell.

"A five-minute routine is like a 20-minute aerobic workout," added Reitzell.

The Nereids practice two hours a day, four times a week in a workout that builds aerobic conditioning, strength, endurance and breath control. They also rehearse routines on land to perfect their timing.

But even with all the stress on competition and skills, synchronized swimming is still a water show. The girls wear matching bathing suits and sparkled caps. During the routines, music (usually 10 to 12 short selections of rock tunes) blasts through speakers. To observers, the swimmers' wide range of skills appears less important than their constant smiles.

Olson recalled a time when one of her swimmers broke her bathing suit strap just before competition. She performed the whole routine, upside down and turning around, with the strap in her mouth and a smile on her face.

"They're always ready to do a show," Olson said.

All of this dedication is part of the team spirit. Although much of synchronized swimming is an individual sport, perfect group synchronization is difficult without a tight kinship among the athletes. Other members of the eight-person travel team are Susan Lappenbusch, 16; Melissa Ganley, 15; Stephanie Monroe, 15; Shanon Karr, 15, and Lori Pharo, 15.

"I quit for half a year last year and missed it so much I had to come back," O'Donnell said. "We're all best friends."

"When you get out there (in the trio) you're trying to present yourself as one," Ulrich added. "If you don't like each other, people can tell."

On stage, in the water, the Nereids have the skills and the smiles to perform water shows with top national competitors. They take the sport seriously because people finally are realizing that synchronized swimming is, indeed, an Olympic sport.