Clark Campbell has seen it every four years.
As the American swimmers haul in medals during the first week of the Olympics, local swim clubs get flooded with calls from parents who believe their children can be the next star to wear the goggles.
Then things die down, only to ramp up for the next Olympics.
"It's very cyclical. Whenever the world's attention is on something, you're going to get a lot of new interest," said Campbell, Kansas University's head swimming coach.
This time, Campbell says, things could be different because of one man, Michael Phelps, the 23-year-old who has become the most decorated Olympian of all time.
Phelps might just keep the sport charging into the mainstream like his flailing arms down the stretch of his thrilling 100-meter butterfly race - where he pulled out another gold by 0.01 second.
"We're getting to witness our Michael Jordan of swimming," said Campbell, who became a swimmer when, as a 6-year-old, he watched Mark Spitz earn seven Olympic gold medals in 1972.
Swimming enthusiasts say Phelps' accomplishments have already given the sport a major boost.
Mike Soderling, head coach for the Lawrence Aquahawks, said the team has been swamped with calls even though it won't enroll new swimmers until Sept. 8. Soderling has 175 swimmers on the team, and he hopes to get back up to 200.
The team typically takes new members ages 7 to 11 who have had lessons and can swim freestyle and the back stroke.
While the sport's popularity has ebbed and flowed in the past, usually with the Olympics, Soderling said Phelps' popularity is sparking more interest.
"What he's doing is bringing a lot more understanding of how difficult it is to be a great swimmer," he said. "Having an American who is that dominant really inspires people."
Soderling has coached some excellent Lawrence swimmers and even watched Phelps at national meets for about eight years. But the national interest seems to be taking hold for the sport, especially with the crowds who watched the Olympic trials earlier this year in Omaha, Neb.
"The key for us is getting people excited about the sport and keeping them in there," Soderling said.
One of Soderling's top swimmers, Aquahawk Molly Albrecht, a Free State High School senior, said Phelps and the other U.S. stars have made a splash with many of her classmates, who buzzed about them last week at school.
"Michael Phelps is amazing, obviously, and it's really cool. He's kind of broadened people's interests in swimming," she said.
KU swimmer Ashley Leidigh, a senior and Shawnee Mission North High School graduate, said Phelps also serves as a role model for younger swimmers.
He's owned up to his past mistakes, like being placed on probation for a 2004 DUI, but he's also moved forward and worked hard to carry the sport, said Leidigh, who swims the butterfly.
Several KU swimmers met Phelps in 2007 in Mexico when they were at the same training site.
"If anything, I think, people always say that swimming is only a big sport and well known for the Olympics, but I think as years go by, it will become more well known year-round just because of what's been done by Michael," Leidigh said.
Her coach, Campbell, said the sport should get more popular, and those involved in scouting the next generation of swimmers will be looking for young athletes who have the drive to stick with it long-term.
"Hopefully you find that next Michael Phelps out of the 6-year-old boy who comes to the pool," Campbell said.