The sewage-filled waters off Copacabana weren't much of an issue for the open water swimmers.
"It tastes like ocean," American Haley Anderson said nonchalantly.
Instead, the women's Olympic race will be remembered for something more familiar in the rough-and-tumble sport — a disqualification right at the finish line that lifted Brazil to a bronze, its first swimming medal of the Rio Games.
Sharon van Rouwendaal claimed gold for the Netherlands with a dominating performance, pulling away over the final lap to win in a romp Monday.
Van Rouwendaal began to spread the margin on the third of four laps, and it wasn't even close by the end of the 10-kilometer race. She reached up and touched the timing board before her closest challenger had even entered the finish chute. The winning margin was a staggering 17.4 seconds, far more than the 0.4 difference four years ago and the 1.4 spread at the inaugural open water competition in 2008.
"I felt so good," said Van Rouwendaal, who finished in 1 hour, 56 minutes, 32.1 seconds. "I swam so easy. I felt no fatigue. After 6k, I changed my mind and thought I should push on."
The bigger drama came behind the winner. Aurelie Muller of France touched next, but then it was announced she had been disqualified for an incident at the finish. Apparently confused, she was about swim into a white buoy when she tried to cut over and collided with Italy's Rachele Bruni.
"She pushed down my arm," said Bruni, who wound up with silver.
Brazil's Poliana Okimoto went from just off the podium to bronze — the first swimming medal ever won by a Brazilian woman, either in the pool or open water. Okimoto's medal eased some of the sting from a disappointing performance by the pool swimmers, who failed to win a medal at their home Olympics.
"This was the best event of my life," Okimoto said. "God is Brazilian."
Van Rouwendaal didn't look like much of a medal contender as she battled an ailing right shoulder for eight months. Finally, about six weeks before Rio, she was able to get treatment in Spain that relieved the pain.
"It's not been a great year for me," she said.
It just got a whole lot better.
Defending Olympic champion Eva Risztov of Hungary wasn't a contender this time. She finished 13th, more than a minute behind the winner. Anderson, the silver medalist four years ago, was more than 48 seconds off the pace in fifth.
With music blaring, scantily clad beachcombers frolicked in the ocean waters on a sunny winter day, though officials on jet skis kept anyone from swimming out close to the course. In many ways, it was just another day at the beach for sun-worshipping Brazilians — with an Olympic event thrown into the mix.
The temperature was climbing toward the low 90s, but the heat wasn't a problem. All 26 swimmers finished the race, a striking contrast from four years ago when two athletes, including Okimoto, had to be pulled from the water.
"London was a difficult experience for me," the bronze medalist said. "I tried to keep those memories away."
The start of the race didn't comply with FINA rules, which require the swimmers to jump off a fixed platform. The Rio structure was destroyed by high waves last weekend, so the swimmers — in a scene that resembled the set of a war movie — waded off in the water, cheered on by hundreds of Brazilian fans.
About 250 yards off shore, they all bunched up together to get the signal to begin four laps around the bay. Fort Copacabana was at one end of the course, while Sugarloaf loomed over the far end of the 2.5-kilometer circuit. A Brazilian naval vessel lurked close by, ensuring there were no security issues.
While the hotel-lined beach provided a glorious backdrop, the race was held in waters that an Associated Press study found could be dangerous to one's health because of raw sewage dumped into the city's waters. Brazilian officials had vowed to clean up the waters after winning South America's first Olympics, but those promises were never carried out.
The quality of the water was a major embarrassment leading up to the games, also affecting venues for rowing, canoeing, sailing and triathlon.
Anderson took antibiotics and probiotics for extra protection, but said it seemed like any other ocean race.
"My tongue is like salty right now," she said.
This was only the second Olympic competition held in open ocean waters. At the first Summer Games in 1896, before custom-built pools were the norm, swimming was held in the Bay of Zea.
The inaugural open water event in 2008 was staged at Beijing's rowing and canoeing canal. Four years ago, the open water in London took place in the Serpentine lake at Hyde Park.
The men's 10K race will be held Tuesday on the same course at Copacabana.