However, this problem was not about the athletes in the pool, but about the men who stood on the deck waiting for their chance to dive.

Synchronized swimming, formerly known as synchronized swimming, caused a stir two years ago with the announcement that men would be allowed to participate in the games for the first time.

World Aquatics called the news “a day for celebration.” Bill May, an American synchronized swimmer who has campaigned for decades for a place for male athletes on the sport’s biggest stages, viewed the decision as the crowning achievement of his life’s work.

“Never, never, never, until I die, will I forget that call,” May said.

But now the Paris Olympics are just around the corner, and the brave new world of synchronized swimming looks a lot like the old one. None of the participating countries actually sent a man to their team. The vision of an all-gender competition in Paris has evaporated. World Aquatics released an embarrassed statement saying the organization was “very disappointed.”

“This should have been a milestone for the sport,” the statement said.

May, now 45, had made an extraordinary comeback to compete in Paris. He was part of the U.S. team that qualified for the Olympics in February. In April, he was feted at a multi-day U.S. team press conference, his legs bouncing with excitement as he sat on the stage.

But when the US finalised its list of candidates in June, May was not included.

“I feel like an opportunity has been missed to finally allow men to participate in the sport and then not have any men there anymore,” May said.

Instead, May was poolside at these Olympics, ceremoniously opening the freestyle portion of the competition on Tuesday. His performance was met with thunderous applause.

Long derided for its origins as water ballet, synchronized swimming is now attempting to emphasize its athleticism and rigor by moving away from its roots as a “synchronized” discipline. One way to do this is to abandon the rigid criteria that only women can participate, leaving rhythmic gymnastics as the last remaining women-only Olympic sport.

The idea behind it is that by adding men, even more acrobatic flights will be possible and thus new fans will be won.

There are a handful of boys and men like May who have trained to the elite level despite the hurdles of international competition. The World Championships in 2015 was the first to allow men to compete in a newly created category of mixed duets. The Olympics took a different approach, allowing countries to put two male athletes on the eight-man squad for the 2024 team event.

Andrea Fuentes, coach of the US team, said “there was not enough time” to fully integrate men into the teams. World Aquatics says it is “absolutely determined that there will be male synchronized swimmers in the team event at the 2028 Games in Los Angeles.”

But it will probably not be that easy. The two men who were long considered the most likely candidates to take part in the Olympics – May and the Italian Giorgio Minsini – have both given up their participation in the Olympic Games in Paris.

Minisini, 28, first got the idea to learn synchronized swimming as a child after seeing May perform at an event in Rome. As he grew older, he noticed that every time May got out of the pool, women would come up to him to take photos with him. That’s when he knew the sport was for him.

Over time, Minisini became more serious about synchronized swimming, eventually joining May as a prominent male athlete championing inclusion. He retired from the sport after failing to make the Italian team for the Games. What gives him hope is that the male swimmers who come after him may be able to do what he failed to do.

“One thing is not being able to achieve your goals,” Minisini said. “Another thing is not being allowed to achieve your goals.”

The synchronized swimming world believes there are men ready to take on May and Minisini’s legacy. Kazakhstan, Spain, Japan and the United States are among the countries that have successfully begun to increase the number of men in their ranks. USA Artistic Swimming CEO Adam Andrasko said the country has three male athletes between the ages of 13 and 19 who are at a “high, high level.”

This gives May confidence that even if it is not him, he will not have to wait long for a man to compete in the Olympics.

“I don’t have the medal or the Olympic experience,” May said, “but that’s not guaranteed to anyone.”

Write to Jared Diamond at [email protected] and Louise Radnofsky at [email protected]