Marathon swimming isn’t anything like it sounds.

First, the Olympic event is not even a marathon; it’s a 10K (or 6.2 miles). The reason it got that name was because it typically takes elite-level swimmers about the same to complete the open-water race as a road marathon takes to run — around two hours.

Marathon swimming Flickr 1

Photo: Courtesy of Bruno Cordioli/Flikr commons

But while marathon swimming is indeed an endurance sport, that’s about where its similarities with distance running end.

Though the Rio website describes the sport as a “bona-fide test of strength, strategy and endurance,” the Olympic 10K open-water swim is also the only discipline “where there’s an opportunity for Jaws to be in the race,” laughs the renowned Steven Munatones, 9-time USA Swimming U.S. National Team coach and founder of the World Open Water Swimming Association.


Open-water distance swimmers tackle oceanic challenges during the Flowers Sea Swim in the Cayman Islands. Photo: Courtesy of Steven Munatones

And he’s not kidding. Sharks are just one of the extremely unpredictable variables that come with marathon swimming, which in this Olympics takes place along the iconic Copacabana Beach in Rio de Janeiro, where water temperatures for the Aug. 15 (women’s) and Aug. 16 (men’s) races could be around 72 degrees and waves could rise to 12 feet if conditions are ripe.

Munatones, who has swum more than 40 times along the same stretch that athletes will tackle, says it’s not the water’s hygiene that Olympians should be worried about, it’s all the other stuff: jellyfish, sea snakes, swells, tides and, surprisingly, jabs from other swimmers who are not afraid to throw a sucker punch when the referee is looking the other way.

“It’s not uncommon for us to see broken ribs, chipped teeth and blood, lots of blood,” says Munatones.

Among the intentional or unintentional penalties, which could pin swimmers with a red or yellow card, especially near the turn buoys where the real action takes place, are impeding, or veering an athlete off an intended straight line; the old elbow check; a kick to the ribs (or other soft flesh part); and the classic zipline, or hooking a hand around a person’s ankle or wrist and pulling back.

These could be some serious made-for-TV moments when the event broadcasts.

Despite all that, both the top male and female American competitors have a serious chance to sweep the gold-medal category.

That may come as a surprise, given that the sport remains niche in the U.S., but is much more popular in other parts of the world. Our top swimmer is Jordan Wilimovsky, 22, of Malibu, the reigning 10K world champion, followed by Sean Ryan, 24, a University of Michigan standout originally from Chattanooga, Tennessee.


American swimmers pass a feeding station during the Pan Pacific Swimming Championships in Vancouver. Photo: Courtesy of Dr. Jim Miller

Munatones says, “The odds-on favorite is Jordan, because he grew up surfing so he can handle any condition,” including the massive waves that are real possibility in Rio.

He’s known to have a high navigational IQ quotation, which in open-water swimming terms means Wilimovsky can swim relatively straight despite barely being able to see buoys or hear much of anything, plus having to avoid competitors who are trying to sabotage his swim with some of the stealth tactics mentioned above.

The sole American female, 24-year-old Haley Anderson, who missed Gold by four tenths of a second in 2012, is also from California, which will give her a huge advantage in the ocean. Plus she’s just that good.

Marathon swimming only became an Olympic sport in 2008, and just 4 years later, at the London Games, Anderson became the first U.S. medalist in the event.

Munatones says the discipline is so exciting to watch because men and women approach the race so differently. “The women can swim very fast for a long time and they race with high intensity for the whole two hours,” he says. “The men, who are carrying more body mass, tend to be significantly slower in the first 2K and save it all for the end.”

During the 10K course, which consists 25 swimmers who begin in a mass start swimming four 2.5-mile legs, with one feeding station per loop and four buoy turns, spectators can expect to see frequent lead changes, as different swimmers who are more adept at swimming with or against the wild tides and ocean surf vie for the top spot.

“The conditions are dynamic and are always changing throughout the race,” Munatones says. And, of course, there are those man-made obstacles. “There are places on this course where you will see extreme physicality — something that’s wholly unknown to anyone outside sport. It’s kind of like boardercross in the water.”

I don’t know about you, but I can’t wait to get a glimpse of that.

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