Entrepreneur’s annual ranking of the 500 best franchises has two swim schools on its list this year: Goldfish Swim School in Troy, Mich. and Fort Lauderdale, Fla.-based British Swim School took spots 45 and 309, respectively. The magazine’s formula factors system size, growth, financial strength and stability.

Both schools are seeing their numbers surge after several years of cautious experimentation with the franchise model. Driving the growth, they say, is a greater awareness for water safety and attractive opportunities for aspiring business owners.

Goldfish Swim School was founded in 2006 by husband-and-wife team Jenny and Chris McCuiston. (Jenny is a decorated swimmer and two-time Olympic trials qualifier.) In 2009, they opened their first franchise and slowly began opening more units as they continued to develop the system. Today, it has 40 schools open and another 25 in development across 22 states.

For Goldfish, coming in at No. 45 represents a huge leap from last year when Entrepreneur placed the school at No. 403. The company also claimed the top spot this year in the children's fitness category. System wide, Goldfish Swim School conducts more than 54,000 lessons a week.

“Now that we have everything down … it’s really, in the last two years or so, taking off to where we’re experiencing exponential growth,” said Ashley Mitchell, marketing manager. “I don’t anticipate it slowing down.”

British Swim School founder Rita Goldberg (second from right) poses with the franchise's 'Instructors of the Year' along with UK Olympic gold medalist Adrian Moorhouse (far left).
British Swim School British Swim School founder Rita Goldberg (second from right) poses with the franchise's 'Instructors of the Year' along with UK Olympic gold medalist Adrian Moorhouse (far left).

Neither does Rita Goldberg. She’s the founder of British Swim School. She closed out 2016 with more than 100 pools in 15 states and Turkey. The school taught more than 475,000 lessons last year – up 100,000 over 2015.

Goldberg, a former national swimmer for Britain, began franchising the 35-year-old business in 2011. Like Goldfish, British Swim School is riding a wave of momentum: Last year, Goldberg didn't sign on any franchisees until May. This year, she already has eight -- and it's only February.

She went into franchising with low expectations.

“I never dreamed of having six or eight (locations),” she said. “It was totally unexpected.”

Both companies take different approaches to the learn-to-swim business: Goldfish requires an investment of $1.4 to $3 million, part of which will fund the construction of a brightly colored indoor swimming pool that employs a sort-of rustic beach house motif. British Swim School, on the other hand, costs between $80,000 and $100,000 to join. It’s less because franchisees rent space at existing pools at health clubs, condos and hotels.

Both acknowledge that they’re facing competition from other swim-school franchises entering the fray. And that’s a good thing.

“The fact that they’re marketing private swimming schools and we’re marketing private swimming schools, we all benefit,” Goldberg said.