LAS VEGAS • In a darkened arena on the Las Vegas strip, swimming is being reinvented.

This weekend, some of the sport's biggest names are competing in the grand finale of the International Swimming League (ISL) after stops in Indianapolis, Naples, Lewisville, Budapest, College Park and London.

The flashing lights, pulsating music spun by an on-deck DJ and action-packed racing is a concept swimming has never seen.

The pro league's inaugural season culminates with the top four of its eight teams racing in a 25m temporary pool at the Mandalay Bay Events Centre and the 14 men and 14 women on the winning team will split US$100,000 (S$135,500).

It is version 2.0 of the Olympics and world championships, a roll of the dice for a sport that struggles to stay relevant outside the Games.

Rivals at those major events turn into teammates in the league, featuring athletes from various countries.

Swimmers are grouped by teams in on-deck box seats, where they cheer on their teammates, who are racing for points, not fastest times.

The only moment of quiet during 19 events jammed into two hours is when the referee says, "Take your mark."

"I love all the smoke and mirrors," American Lilly King of the Cali Condors team said.

The two-time Olympic gold medallist won the 50m breaststroke on Friday night, making her 10-for-10 in her individual ISL races so far.

Australia's Cate Campbell of the London Roar team added: "Vegas is the place to show off and that's exactly what we're hoping to do for the sport."

An announcer in a dress suit bellows introductions and provides play-by-play during the events.

Fans yell, whistle and cheer. The arena lights come on for the races.

Otherwise, it is swirling spotlights in the dark with only the starting blocks illuminated.

Unlike other meets, there are no yawn-inducing preliminary heats and every race is a final.

"These have been some of the most fun meets of my career and I've been to the big ones," American Olivia Smoliga from the Condors said.

"We're talking trash to all the other teams and to come home with a team championship, that's unlike anything we've ever been able to experience before in swimming. That's really cool."

Most of the world's top swimmers who are professionals have sponsors that pay their training and travel expenses while providing an income, while many also earn bonuses tied to winning Olympic medals.

But the league represents a chance for lower-tier swimmers to bolster their bottom line.

"It's giving a lot of post-grads an actual opportunity to make money and support themselves rather than kind of living off their parents, which is what a lot of people, unfortunately, have to do," said King, in her first season as a pro.

The most valuable swimmer in Las Vegas earns US$10,000 and the season's Most Valuable Player gets US$50,000.

But while Campbell has hailed the ISL as a "revolution", it is clear there is a long way to go in gaining traction, with attendance ranging from 1,000 to the United States stops to nearly 5,000 in Europe.

The first of two days in Las Vegas saw plenty of empty seats and a mix of adults and kids, and there was little advertising for the event.

However, Campbell believes ISL has "already made a name for itself", adding: "The most noticeable thing about this league is how much chatter it's creating.

"I've had people who don't follow swimming come up and talk to me. I hope it can continue to build."

ASSOCIATED PRESS